Need advice on how to deal with this situation.

I am currently in an LTR (we are the same age, both under 20) which seems to be going pretty well. I cannot say I am AF but I also do not identify 100% with being a BB. I still do display qualities of a BB from time to time, but I am working to improve myself.

Anyway, she had a sleepover last night which was supposed to be one with just her close female friends. We texted and snapchatted through out the night until a two of their good guy friends show up at 1 in the morning. They also slept over and my LTR claims to have slept beside a guy but had not done anything sexual. I truly believe she did not do anything, but the situation is bugging me to my core. How do I approach this situation and what can I say/do without being a BB crying about his feelings?