Husband's self esteem

My husband and I currently both work.  I make more money than he does which is part of the reason I can't quite convince him that I can stay home with our son.  I don't necessarily think that the woman always needs to be the one staying home.  I'm okay with my husband doing this as well since I believe that we could afford to live on my salary.  My husband doesn't want me to stay home and he thinks I'm nuts when I suggest that maybe he should consider doing it for awhile. He says men just don't do that.  I tell him it's just his ego talking and that we should put our son first.  Any suggestions?