Should I Lighten Up On My Boyfriend?

Me and my boyfriend have been dating for 10 months. When we first started going out, he constantly cheated on me. We broke up for about a month and he wanted to try to work things out. I took him back because when we first got together , i didn't know him that well. As the months passed I would find other girls he was talking to and pictures of many other females. Although this happened , maybe more then 12 times , I still am with him. When we hit our 9th month , I noticed he has stopped, or at least calmed down. I deleted his Facebook and go through his phone all the time. This weekend I found 5 new girl's numbers in his phone. I am a very jealous girl, and I also catch him looking at other girls, while he is holding my hand! I love this boy to death but when i ask him why he cheats, he says because he see's me only 4 days out of the week and he has "temptations". He is a very sweet boy at heart. We plan to move in together and soon have children. I find myself questioning if that is what I really want. Any suggestions?