He's in Iraq, She's cheating...What should i do?

no, this doesn't make you a tramp. you can't help who you fall in love, but no matter how you try to explain it, your friend will see it as you took her man. don't let that stop you if you really like this guy. this woman made her bed & now has to lie in it. don't ever let anyone stand in the way of your happiness. you're not a bad person, or you wouldn't be worried about all this. good luck.