Preface: I know that I need to talk to the couple involved, but right now I'm just in a major guilt/self-blame spiral and I'm looking for some outside perspective.

I'm a relatively experienced poly person (30 GF, poly for 7 years). I have 1 comet partner, and some local partners. Recently I began seeing a married couple - I'm their first polyam relationship, and I'm dating them as a couple (which isn't how I prefer to date - it's because it's what they want). All conversation is via group chat/group DM, and we only hang out and have sex the 3 of us.

Since I've started seeing them, I've seen them more than any of my other partners or friends, sometimes 2x per week. While I really enjoy my time with them, I'm realizing that I've been feeling they've been bogarting too much of my time, especially since I don't want them to be my primary relationship (for several reasons), but they've told me I'm their priority. So I feel obligated to give them my time, but I'm starting to feel smothered. And resentful that I've had to say no to friends and other partners to accommodate them.

They've told me they understand that I date other people, and that I'm looking for a nesting partner/primary attachment figure to form a family with (which isn't them). They've also said that I can always say no to requests to hang out.

But recently I was told that they feel like I abandoned them. I apologized, and expressed to them that I can't keep up the texting all day/seeing them more than once per week cadence we had for a bit, but I feel guilty for not being able to give them what they want without going against my own desires.

It's frustrating because neither of them have been the 'third' and it's like they think dating them is just like dating 1 person. It's not.

I feel guilty because they tell me that they prioritize me...but it's not the same. It feels like they're lying to me, because I know they TRULY prioritize each other. It's like they don't understand how it feels, not having someone who's your 'rock'.

But I do care about them, and I like our time together, but I'm also angry at myself because I feel like I led them on - I had some rough patches personally when we were together, and they've been supportive of that, so I feel like I owe them attention/love in return...but I just don't feel as strongly for them as they do for me. So I'm just awash in guilt.

Was I the asshole for dating a couple, going against my personal preferences? And am I an asshole for not being able to reciprocate their intensity of feelings, no matter how hard I try, and feeling resentful to a certain extent that they have each other?