Dude, Same shit happened to me... (she was a server and he the cook at a country club)
1. Dont Fight him I, I caught her in Nyohs with him, walked
out never looked back.
2. Loose any of her friends, fucking one would be awesome, but
then you have more drama to deal with.
3. Start drinking more... this is partially how I came to PRK
4. Find a new hobby... like the gym.
5. It will prob happen again.. so be ready for a repeat..
6. and for me the only thing to expect in a relationship is,
Lies, Cheating, and Dram... if you find one with out these
keep her!!!
Sorry to hear man, good luck!