Sex, like any other area of a relationship, relies on open honest communication as a basis to be comfortable and grow together. Being you went so long with just sex, you must now get to know each other as people and reach the level of talking and listening to each other so you both can benefit. The day in ,and day out drudgery of life, with kids no less, can wear on any couple, but you must mutually make time for yourselves, as that spark can get buried with out either of you realizing it. So to answer your question, No I don't think there is anything wrong with his sex drive, it has just been suppressed, because the home life is not allowing him to express his desires. What can you do? Babysitters on his off day, where you have time also. Go back to the things that brought you together when you had only benefits. Show him he is number one. Hope this helps.