I'm going to assume that you haven't been separated long and all of this is new to your kids. I went through the same thing with my 7 year old boy and also had a 4 year old girl at the time of the divorce. My boy was old enough to realize what was going on and didn't like what was happening in his world. He had a hard time accepting it and getting into a new routine. I suspect this is what your son is going through as well. In time he got used to the new routine, but it was very hard to watch him go through that phase. I kept blaming myself and trying to figure out why he wouldn't want to spend time with me. I think its just a natural thing for the kids to want to stay with mom. Most kids that age still find more comfort with their mother than their dad. Hang in there, and give him reasons to want to spend time with you. He will come around, as my son did. Now he loves to spend time with the "ole man" (he's 8 1/2 now).