How long should I wait to be intimate with m boyfriend after he kissed someone else?

[Sarah]

My boyfriend went away last weekend with some old college friends and ended up getting extremely drunk and kissed another girl. He was drinking all day with his old fraternity brothers, all of them behaving badly, acting like big shots, he ended up telling me right away after it happened and got himself out of the situation right away and continually tried calling me. The next day he felt awful, I recieved many messages about how awful he felt and how sick he was with himself. There was talk of going home with this girl but he said he came to his senses and got out of there right away. I am glad he was honest with me and I have decided to forgive him after he showed up after he returned from the weekend to my place. He drove a total of 9 hours to see me when he only had to drive 6 back to his place - he stayed the night we stayed up four hours with me crying and him crying and promosing me this would never happen again. He had to wake up at 4 am the next day to get back to work. This whole cheat all happened on friday night, saturday he felt awful and didnt kiss anyone else but he did text me all night long numerous things that had happened. Such as girls who would come up and kiss him on the cheek or hug him. He also danced with a group of people saturday night some including girls. He told me all this saturday as well. Told me he would never go back there without me, this weekend taught him he wants to marry me and that I am the girl for him. Our first date was at the beginning of august and we became official in february. This whole event just happened this last weekend. He has told me he will do whatever it takes and showed up sunday night with a dozen roses and sent me flowers the next day to my work as well. I have decided to try to forgive him but if he ever messes up again i am gone. I am just wondering how long i should keep him in the dog house and how should i do it. I havent slept with him yet, i was planning on doing that this weekend but now that is not going to happen. Should i even kiss him this weekend? How long should I make him wait before I do anything? What should I do please help!