My husband and I have been together 7 years. Married for 5. We have a son together and custody of his 9 year old daughter from a previous relationship. My husband dated this girl when they were like 14. She is his sister’s bestfriend and has always been around for everything. About a year ago, one of his brother’s got drunk and she had sex with him. I just found out my husband got drunk this weekend, ran into her and his sister in a bar and low and behold he slept with her. I’m so pissed right now. She is just plain nasty. She’s been with every guy she meets. Her last relationship was with a drug head. Who knows what diseases she could have. Now my husband is “sorry” and wants me to forgive him. I just lost my job, which was making me miserable anyway. I’ve been depressed for a few years now and this doesn’t help any. I look at my son and just want to cry because deep down I know the right thing to do is leave, but how?