My personal belief is that our intuition can often act like a superpower. In reflecting on my life, and experiences where it provided warning (that I didn’t listen to), I now realize it was right. I don’t doubt that yours is warning you.

More context to your relationship is probably needed but from what you’ve written, I feel like something is definitely going on. You have the texts that prove it, much less the bad feeling you have. You can confront her or you can continue to look the other way. Often we look the other way because we are scared of the unknown that the confrontation may bring (but surely it is better than being deceived and disrespected).

Ask yourself what kind of life you want to live and the answers may come to you. Trust, honesty and communication are essential pillars of any successful relationship though. Don’t deny yourself those basic needs.

I feel like there may be some boundaries being crossed in your relationship. You may not want want to care that she hangs out with this person alone, but the fact is that you DO care and it makes you uncomfortable, and your gf/fiance should respect that. At the very least, she should include you. If she’s deleting texts, she’s hiding things from you, which is not a good sign.

Also, you said “I don’t care about being lied to,” but I think that is something you very much should care about in this case, because being lied to, especially when it comes to an ex-lover, is a breach of trust. We all tell lies from time to time to not hurt others’ feelings (like “I love your new haircut!” even when it actually looks awful), but there are some things that should just not be lied about in a relationship, and that’s one of those things.