See my previous post here.

TL;DR for last post:
1 week ago my wife revealed she's no longer interested in participating in sissy stuff with me and asked if i'd be interested in opening the relationship so a) she can be with a more masculine guy sexually and b) so I can freely explore this side of myself as well.

TL;DR for this post:
Well, yesterday there was a big development and I think things are going a little fast. Short version is she had already met with a guy at the end of August, met him at a bar, then made out with him. I'm seeking advice on how to process this (4 questions at the bottom).

Here's the full explanation:
At the beginning of August, we were at an event where my wife saw a guy who she admitted to me looked extremely hot. I was flattered because he's the same type as me, and looks similar. I playfully teased my wife and offered to introduce her but of course she chickened out. And I didn't think much of it, because I trust her and was never worried about her cheating on me (we've been married 7 years). She was a little bit high and drunk when we were at this event, and I mostly attributed her comments to that. But apparently she was extremely into this guy.

We leave the event, I think nothing of it. But what I didn't realize was that she began looking this guy up online and then added him on Instagram. They then began texting and eventually exchanged nudes. I have no idea this is happening and I find out later (stay tuned).

Then at the beginning of September, she tells me everything I shared in my previous post (link above). Basically wants to end the sissy stuff together (has been feeling like this for a while, apparently), then suggests being open to new experiences apart from one another while keeping the marriage intact. I admit to being freaked out, but slowly start to come around because she's saying that I'll be able to also explore stuff. Mind you, I was content with the prior arrangement (infrequent sissy stuff together) but wasn't aware that it was getting less and less interesting to her. Also - a very important fact. During this conversation, she did *not* reveal that she had flown out to meet this guy and made out with him (more on that in a second). I even asked her: "do you promise you don't already have a guy in mind that you'd like to do this with?" And she said no. So I was thinking she'd have to create a dating profile, etc., and we even logistically talked about that happening.

Ok so now we get to yesterday. She asks me if she can talk to me about having someone in mind who she'd like to do this with. And I jokingly guess that it's the guy we had seen at that event. To my shock and surprise, she admits that yes I was right, and that she had already flow across the country to meet him.

I was floored.

Turns out that at the beginning of this month, she met him during a personal trip that she took to the other side of the country. I was under the impression she was just meeting with friends and reconnecting with some of her past (it was a part of the country we used to live in). But she admitted that one of the main reasons for the trip was to meet this guy.

I'm still trying to process everything. We had this conversation in the morning yesterday, I had to completely cancel all my work meetings and take the day off I was so overwhelmed by this information and we literally discussed it all day long and into the night.

She apologized profusely, and admitted it was a terrible thing to do (because we hadn't yet fully agreed to open the relationship). And because she had lied to me.

But she's also wanting me to explore my stuff separately so I think she feels like it's sort of making up for the betrayal. Which I feel like should be beside the point. I'm open to that idea of me exploring separately but we're just moving really fast. We've already drafted somewhat of an agreement between us, and she's going to meet with this guy again. Because I feel like she'll eventually resent me if she doesn't get to do this. And she thinks I'll resent her if I don't get to express myself more.

Today - she's going to text him and see if he agrees to the rules she and I have agreed on but I really just still need to process how quickly this is happening. And i feel like I want to get more of an apology from her.

Yes I admit the idea is kind of exciting to me but this is a very serious matter and I want to make sure she's treating it that way.

1) Am I wrong for being upset about this betrayal? We hadn't opened the relationship yet.
2) What should I do to ensure she doesn't betray me again like this and potentially escalate the relationship without me knowing?
3) I feel like my trust has been violated. Am I right for feeling this way?
4) What would you do in my situation?

Thank you all in advance!!