T.S.
Hi M.- I just wanted to let you know that when my husband and I got together (dating) my son was 5 and my daughter was 3 1/2. My husband and I have been together for 12 years now (10 years engaged and almost 2 years married) and my kids have formed a bond with my husband. My husband will tell you that he fell in love with my kids first before me. My suggestion to you is hang in there don't give up. It will work!!! I know my son and my husband enjoy fishing together (just them) and they have went to ballgames together (Nebraska) and they even have played softball together as well as my husband coaching for my sons team. Bonding time for them two should just involve those two. I know that the time they spend together will become quality time and they will both find out what they have in common.
I hope this works for you, I know that it did for my son and husband and even my daughter...(my husband and daughter do this as well). Good Luck