<human>: Condense the text into a few key points

Hi guys, 

I'm at a complete loss and my mind is all over the place right now. Hoping someone has any advice at all really..

My fiancee and I have been together for 5 years now. Prior to this relationship I was cheated on by my ex. My fiancee and i have always been close and rarely argue. 

We've pretty much had one group of friends but she could go out with her girls I could go out with just the guys. Great!

Now the problem.. I went away for 5 months to finish university(coming back every so often) and while I was away she started hanging out with two other guys and one of her girl friends. 

I was fine with this, until I noticed her delete messages from one of the guys when I was next to her. 

I eventually confronted her about this and she's told me it's because he texts her things like "thanks for the blowjob last night" or "nice ass" and so she didn't want me to get the wrong idea. Apparently nothing has happened that's just "how the guy is".

We spoke and I've pretty much said I don't want him messaging her like that. But they still go out together with a few other friends I don't know.

Thing is, they could be just flirty friends, but I don't think I can trust that.. I'm pretty sure she's still deleting messages (I refuse to snoop). 

I don't know what to do. I'm back now and she is seeing this other group of friends twice a week. If I ask her what she got up to it all sounds very scripted. She always mentions that it wasn't just her and the guy..

In my mind, it's like she's falling out of love with me, she's loving a single life style and is just slowly transitioning herself away until she's fully decided she wants to end it... Am I being completely paranoid and stupid? 

I know I'm pushing her away every time we talk about it which is even worse.
<bot>: Fiancée going out with other guys and girls. One guy flirts with her a lot. She deletes messages from him and always snap chatting. I don't like it but don't want to lose her...