First LTR and it's going 4 months great.

We go to college together and have a few classes together as well.

Anyways while studying yesterday I noticed her receiving texts from a guy and she wouldn't open them when I was explicitly able to see. She would reply quick and that was that.

So today I acted pretty aloof and didn't say much. She picked up on it because normally I'm not the silent type. Few hours ago she sucked my dick good.

She left her iPhone in my room and I unlocked it and looked at the task manager thing when you double click the home button. In the recent contacts was his name but the text message conversation wasn't there. Not really sure how iphones work but if someone is in your recent contacts and no phone call or messages are there it seems like the user may have deleted the call/messages. I looked up the guy on Facebook and he is a type that my gf wouldn't go for as far as I know. Looks weren't great or anything so I'm not threatened by this guy but why would she delete the conversation?

Do I confront her about this, and if so HOW without looking like a snoop?