We have two weeks until our wedding. Just when everything seemed fine, I noticed that my fiancé liked a photo of his ex on Instagram. Plus, this isn’t the first time! He had said he would stop doing this when we talked before. What should I do now? This incident shook my trust, but I can’t bring myself to break up when everything is ready.
I’ve experienced something like this. Being obsessed with exes doesn’t do anyone any good, seriously. The explanations afterwards wore me down even more. I suggest you talk, but these things get tricky closer to the wedding 
How many years have you been together? Does he do this all the time, or did something like this happen in between? 
@camkenari actually let’s say 3 years, this happens to us with serious things at first… but I thought we had already discussed a liking situation earlier and it had been resolved.
@soncaykaldi it seems resolved, but it isn’t. I mean, it should be said once, understood, and then not done. If it keeps repeating, it feels like they aren’t taking it seriously. Don’t mention weddings or anything, if there’s no trust, it won’t work.
Actually, thinking of such situations as just social media likes is generally misleading. The main issue is your partner’s emotional attachment and the consistency of their behavior. If this is a dealbreaker for you, you should express it clearly 
How did we get into so much detail? Is someone who likes their ex really ready to get engaged, friends?
I will break the engagement.
So what kind of photo did he like? Is it from an ex’s wedding, or just a regular post? If it carries a special meaning, that’s really a problem, but can you really make a big deal out of it if it’s just social media activity?