people go back for many different reaons. Cheating is not a relationship ending discretion for all people
I would not tolerate that.<br />
I would guess fear, desperation, insecurity, a willingness to forgive (forget-I don't think so), loneliness. <br />
Some would say love. <br />
Again, I would not tolerate cheating. It is undesirable beyond words.
people tend to go back to the cheater because they tend to have something over them. The second reason is that the person cheated on feels like it is something that they did and can be a better bf/gf thus making it easier in their mind to go back to the cheater.
They love them. <br />
They cling to what's familiar.<br />
They're insecure about getting someone else.
Because people are capable of change. We don't just say oh you've cheated? I'll be home at 11. Break up is off by the way. No. There's talking. Crying. Hitting. Swearing. Talking. Talking. Talking. Laying of boundaries and then the long process of regaining trust.
Maybe the sex was really good.
They are unwilling to experience the pain of a breakup, not realizing that the pain will be worse at the end. Once a cheater always a cheater.