set aside time for the both of you- have a "date night". make/buy something that is special for supper (after the little one is fed and in bed), open a bottle of wine or have a beer, rent a movie that you two want to watch. kill the lights, light some candles, take a bath/shower together... spend some time getting reacquainted, and enjoy his company... a little time investment that is not "family" related goes a long way. for the both of you- make time even when you ARE tired, its important.
i guarantee you, that if you show some affection, gentle touches, physical closeness, attention to his needs... it'll pay off. + if you get him hard you can use him regardless. lol
seriously though, schedule time for the two of you that is for nothing else, and just see where it goes.
i have 3 kids, and my SO works INSANE hours. we still manage to find the time... just make it a priority.
at 2:32 PM on Dec. 27, 2009