BF ex GF went as his plus one to a wedding.

Perhaps the dates of the photos you stalked at not correct.

She would have received a wedding invitation along with him when they went out, before they split.
After they split it would be her choice whether to go or not, she wouldn't be his +1.
He could probably have told her he didn't want her to come, but it would be her right to go as she received an invitation, and he couldn't stop her.
If she was friends with his family, she probably wanted to go.
But, you seem to have other problems anyway.

Perhaps she was a friend of theirs anyway, and of course seating would have been sorted before they split

More likely she had her own invite after they split and she was already next to him on the seating plan? That doesn't make.her his plus one.

After 3 months I would expect you to be his +1

I wouldn't. And on most MN threads about inviting couples, most say they wouldn't invite someone's new partner, especially if they haven't met them themselves. These days, I hardly ever hear of generic "plus ones" at weddings - they cost too much!

I think there are way too many possibilities and questions to be asked and answered. How long had they been a couple? Had the invite (obviously received while they were still together) been to "Boyfriend + guest" or "Boyfriend and Name"? being the two most immediately relevant.

"Maybe they are friends? I’m still friends with my ex. I can imagine going as his +1 to a wedding."

An ex invited me to a wedding as his plus one when we were already finished. I declined as I thought it would be quite embarrassing for everyone to think we were together. Obviously, he wouldn't have done this if he'd had a new girlfriend and I would have been even less likely to accept in that situation, even if he had.

You're presumably talking about exes who are both still single, which is completely different.

how long were they together?
wedding invites often go out months in advance

Juells - more likely he would be invited to his own cousin's wedding with ex as a plus one, though.

Op..judging from your update id say this isnt a relationship thats going to go anywhere. You know deep down what you need to do.

Doesn't sound like it's worth hanging in there.

But I just find it weird that she went, and that she thought her invite still stood. - how do you know the invite wasn't for her, and he was her plus one? The ex-GF may have been close friends with the bride or groom.

What do you mean when you say you don’t feel like part of his life? Have you met his family and friends etc, as his girlfriend?

I’ve been in a similar situation which is why I ask, and it turned out my boyfriend who I was living with was keeping my existence a secret. In fact I think I was probably his OW without knowing it.

If you’ve been having relationship problems since you met then it’s really time to call it a day.

Sorry Op but sounds like they were still together. After 3 months I would expect you to be his +1. If she was invited in her own right then I would have expected him to tell you. Why hide it from you? Why were you late night FB stalking? That sounds a little off too
Op?

@midnitescribbler good point, I am in awe of your superior grammar skills and what it adds to the discussion

Maybe they are friends? I’m still friends with my ex. I can imagine going as his +1 to a wedding.

I really don’t see the issue here, unless there’s a big back story. Does he otherwise see her? Are they in the same social group? Is it because he didn’t invite you? It seems less pressure to invite a friendly ex than a new GF. But maybe you’re worrried he's still in love with her?

Are you sure of the date of the wedding, that the photos you saw weren't loaded up 3/4 months after the wedding?

If you felt pushed back for nearly a year then that's a bad sign in its own right. How long was he with his ex and why did they split up?

It sounds as if this is the least of your problems. From your update I’d then be wondering if he actually wanted to still be with her and continuing with the plus one arrangement gave him the opportunity to to work on her and at the very least be with her for one last evening. I think you’re right to call it a day.

Flagfish
I totally agree it wasn’t past. I’m trying to say that how he may have categorised it. But from what op has posted, it’s not this at all.

From your update I would cut your losses and move on. Relationships should not have "problems from the beginning" – it should be the opposite! It doesn't sound like you feel very secure in how he feels about you and surely you don't want to spend the rest of your life wondering if he's that into you?

But Mummy, this wasn’t a ‘past detail’ when it happened! The bf had been seeing the OP for about three months, he went to a wedding and didn’t tell her that his ex came too!

Even if she had an invite in her own right (unlikely), the bf should definitely have said something about it. I’d be gutted OP.

I agree with habibi about blurred lines and not to dwell on this if you are feeling secure in the relationship. It’s the hiding of the situation I’d be upset about. Perhaps have a chat about it and say you’re disappointed he didn’t trust you enough to tell you either st the time or since. Chances are if you’re happy together he was too nervous at the time and forgot about it since as it was irrelevant to him. My dh would definitely does not remember a lot of details about the past including things, which are burned in my brain.

My now husband travelled long haul to attend a wedding of a mutal friend with his ex at the beginning of our relationship.
I think the lines are blurred a bit when relationships start and end close together.
As long as you feel secure now, I wouldn't dwell on it.
It's not like it was last weekend and there's pictures of her on his lap.

Ironic though, that MidniteScribbler can't spell her own first name correctly whilst criticising the OP's grammar.

Please get more information before you come to any kind of conclusion. Good luck!

I don't think I could ever post on here.my grammar is shocking!id be slaughtered.