I'm (late 30s M) not looking for anything as pithy as AITAH. I'm looking for insight and nuance. I'm relatively new to the ENM world, tend to believe it includes the right dynamics for me, but haven't lived it long enough to know. Sorry for the length. I also just need to rant a bit. tl;dr at end.

I spent most of 2023 roster dating (for the first time after a long marriage), for lack of a better term. Some partners I saw 1x/mo, some 2x/wk, partners faded in and out , some were flirtatious, some NSA physical/kinky, some romantic with markers of long-term compatibility. I had zero intention of finding a long-term partner. Everyone was very clear that dating others was fine; most were actually dating others; some caught feelings which tended to end the relationship.

November/December I, to my great surprise, started falling for the partner (let's call them Alex, early 30s F) who I happened to be most long-term compatible with. We had talked about romantic philosophy - both believed ENM could work, were skeptical poly was sustainable for most people, both eventually thought we'd land in monogamous/ish partnership, neither ready to be exclusive/monog at that point (both out of decade relationships within last 6-12 months). We each provided some transparency on how many and what type of other partnerships we had going and got much more transparent about our sexual health boundaries with each other (very safe) and others (her very safe; me safe via testing and sharing history but not always protection). Alex casually mentioned an ex-partner (let's call them Casey) who was trying to rekindle things and making it awkward in their mutual friend group because Alex wasn't interested.

By Dec/Jan, what had been 1x/wk dates had turned into seeing each other 3x week and it was awesome. We were making plans months in advance, doing more mundane catching up on each other's day, having quiet nights in rather than just big date nights, and meeting each other's friends. We were also texting enough that it was pretty easy for me (and prob Alex) to tell when the other was on a date because text would go dark from 6pm-8am. We would just say 'I had a date' if one asked what the other did on Friday etc. It was good transparency, not interrogation. The casual familiarity felt great and the passion/sensuality/intellectual connection were as strong as ever. I decided I wanted Alex to be my primary romantic partner and had candid convos with other partners that 1 of my partnerships was getting more serious which resulted in most of them ending amicably. A couple times, Alex mentioned going out with the friend group that included Casey.

Mid Jan. I shifted the energy in the relationship when I shared with Alex that I wanted to create enough space to figure out how deep my feelings for her and had wound down other relationships. Alex seemed borderline giddy, but didn't reciprocate with similar words on the spot. I read that as Alex being worried I was about to ask for monogamy, which was never my intent. Over 1-2 conversations, we reaffirmed that neither wanted monogamy at that time - I intended to pickup dating again once I'd devoted some time to exploring our relationship and they had one on-again/off-again fling but was off the apps/not seeking additional partners. We affirmed that we both saw long-term potential in other but didn't want to rush into too much.

Late Jan., we were prepping for a big trip and Alex requested that I triple-check sexual health. I did that and Alex asked to shift our sexual boundary to be each other's only unprotected partner to which I happily agreed. Big trip was amazing - figuring out you love spending every waking moment for 4 days with someone is different than popping in/out for 12 hours for dates, lots of fun/laughs, passion, very vulnerable conversations about our traumas/insecurities, and for Alex a massive step in her journey to recover from a major physical trauma (whole trip was planned around an activity she never thought she'd be able to do again). Serious talk (for the 3rd or 4th time) about me being committed to learning how to support her on that journey/her not needing to pretend it wasn't a big deal.

The one surprising bit of information that came out on the last day of the trip was that Alex's 1 other partner (the on-again/off-again one) was Casey, who I had been told was interested in rekindling with Alex but not the other way around. Alex said she owed me more info, given how our relationship had evolved, but wasn't ready to share yet. I expressed that I needed more transparency than typical (and my need/comfort is high anyways), because I felt like Alex not connecting the dots between Casey and the 'on-again/off-again fling' bordered on dishonest omission (the first, more to come). I also talked myself in a graceful interpretation that that level of transparency was pretty new for us so maybe we were just catching up.

Kept up the pace/momentum from Jan. after the trip.

- 3-4 days after the trip, I arrived to pickup Alex for a date and they were changing sheets. Turns out she had been with Casey the night before. Bit of a gut-punch since we hadn't cleared the air but perhaps also not outright dishonest (but sort of omission #2) since we weren't monog and I knew Casey was the other partner. We had a great date doing a bunch of our favorite stuff (drinks, dinner, concert, dancing, making love).

- Later in the week, we had a pretty normal takeout movie night.

- Couple days later, big night out (basketball, bar, dancing). Lots of sensuality but no sex because Alex had a yeast infection or UTI, possibly due to the introduction of me as an unprotected partner over the last week or 2. Neither of us interested in having sex that isn't pleasurable for everyone. Bummer but pretty normal part of a relationship. At dinner, she said she was ready to catch me on the Casey issue, but I asked to defer because I didn't want to put a damper on a great night and we were already 5-6 drinks deep, which is not usually a good recipe for a thorny convo.

- Next morning (we had spent night together), she had plans with work friends and we were going to meet back up at Superbowl party with Alex's friends including many I hadn't met yet. Found out at Superbowl party that in addition to work thing, she had met up with Casey. This definitely felt like a lie by omission (by now the 3rd one) since we'd discussed our plans for the day a few hours before and at other times had no prob saying "I'm meeting up with X" or "I have a date."

Alex's best friend got dumped that weekend which blew up our upcoming Vday double-date plans. We decided to hang the day before Vday to get some "us" time to make up in advance for Vday being focused on best friend consolation. The day before Vday, Alex said she was exhausted from work and brother was in town unexpectedly so needed to cancel our chill night to get dinner with brother and catch up at work. Alex's texting fell off unexpectedly after dinner with the brother. I saw Alex the next day and, after too many drinks to have the conversation, asked if she ended up with Casey the night before... which was supposed to be our night. She confirmed (said no sex though) and we had a long emotional (hurt, angry, but still calm) convo that there was no way for me to view that except as a lie (#4 or so). Basically, she cancelled plans with me, fed me a story, and saw her other partner who definitely felt "on" not "on-again/off-again," (#5 or so) and with whom she a long, but still-undisclosed history with. Boxed into a corner (not literally), Alex tried to give me the history with Casey. Between the beer and the emotions, only part of that message was received.

We decided to keep working through it and keep our Saturday-after-Vday plans which was mean to be our 'real Vday' and was as romantic a night as it could be (gifts, roses, formal dress, big show, dinner). We recapped some of the discussion from before, but didn't go into depth. It was an utterly fantastic night. Again, sensual but not sexual because UTI/yeast infection still hanging on. Again, I get it, but feeling pretty sexually frustrated (2 weeks at that point) which contributed to doubts that were creeping in anyways.

The next week, Alex was traveling for work, getting crushed at work in a job I used to do too, and we talked on the phone almost every night (a lot even for us), just decompressing about our days. Plan for Friday was for Alex to travel back, get dinner and spend night with their sister. Saturday we had plans for a date, sleep-in, cook breakfast. Thursday, Alex said they needed to cancel Saturday because she was overdue for a girls' night, including with recently dumped bestie. Friday came and texting went suspiciously dark after Alex landed. I asked Saturday about it and she cryptically said her sister and her were both tired from their long weeks. At that point, I didn't know if she had even seen her sister much less slept over. Saturday girls' night, she mentions the possibility of meeting up for loving after, texts go suspiciously dark (on a girls' night I'd usually get fun/drunk texts). Sunday morning she says her phone died and she slept at best friends. I've got alarm bells going off.

I arrive Sunday for our delayed date and she says we need to chat before I go upstairs to drop my stuff in her room. She immediately says she lied about the night before because she didn't know how to share via text that she left the girls' night to be with Casey and they had sex. I asked about Friday and she admitted he had ended up at her place Friday after she visited her sister. I've lost count of the lies at this point. I'm crushed about the dishonesty, I'm crushed about having the realization that Casey isn't on-again/off-again or a parallel romantic partner but probably the primary one, I'm crushed about some of the lies being specifically to pick him over me on nights we had plans. I don't believe it's simple jealously about not being able to handle ENM (and at this point I'd gotten back to dating bit).

I mustered everything I could to not react emotionally and talk it out... because I'd crazy about her. We had a long convo, that was so difficult, she finally leveled with me on everything, we have the best transparency we've ever had (much overdue), and I actually have a really good understanding of why she's so attached to Casey and why their relationship (admittedly toxic) is hard for her to let go of because it relates really specifically to some of her deep traumas and vulnerabilities. We still went out and had a good time (I compartmentalize well) and sensual sleepover (but sex def wouldn't have felt right).

I want to be with her. I might be able to get over the lies and the pain and wipe the slate clean... once. I've never thought I could handle a poly relationship and now find myself in something like a poly-V. It's even less likely I could form a poly relationship coming into something with so much history, complexity, and codependency between the hinge and other partner. I definitely can't handle a poly relation that I didn't consent to and has so much dishonesty around it, even if we're now on the level (and I do think we are). I think it would be hard to even do primary romantic/hierarchical ENM with new partners and impossible if Casey is around at all.

Pretty sure my only option is to share that I'm not comfortable with the current state of affairs, need to bow out, and will leave the door open if she ever wants to try to repair and rekindle the great thing we had.

Do you see any other options? For those who've lived ENM for a long-time, is this normal 'new to ENM' growing pains or a massive red flag? Is there actually a health version of ENM that isn't just casual F-buddies?

tl;dr - Trying to navigate ENM for the first time with a non-casual partner with long-term potential for romance and commitment. Feel like there's been too much dishonesty to continue right now... and maybe too much to ever repair. After lots of anguish, finally feel like we have open communication/transparency, but can't put the cat back in the bag. What do?