Hey Dex...my friend...I say this with all due respect bro, but grow a pair. If you think she's screwing around be a man and confront her about it, face to face, and tell her you'd appreciate the truth and look her right in the eyes when you do...you'll know in a second or two the REAL answer, no matter what she says, and mentally prepare yourself for the worst. If what you suspect is true and she confirms it, turn around and walk away. Not a word. Trust an old guy that's had WAY too many chicks come and go in his life...There's no need for subterfuge, or BS puddy 'puter hacking... be bold and be a man. They come and they go, they go and they come, if there's any doubt bro, she ain't the one. There will be many more pass thru your life before it's all said and done. Respect yourself.

"I've had my share of women...lived with a few for awhile, but I ran em away, and they'd come back someday, and still could manage a smile, just takes awhile....just takes awhile." Jimmy Buffet

BTW, bro, I am truly sorry for you having to go thru this.