Maybe while you wait in line for the characters, he can go off and do something else. It's probably not the characters that bother him, it's probably the lines to see the characters.
For example, when your daughter wants to see the fairies he can take your sons to get some ice cream, or do something else.
Maybe you can do a character meal with Mickey and the Gang, instead of waiting in line to see them. Then, he gets to eat (something most men love) but your kids get to see the characters.
My husband LOVES Disney, but he doesn't see the point of waiting in line to see the characters. We don't have kids yet, so it is understandable. He, however, is perfectly ok with the walk-up characters, so maybe you should skip the ones with the huge lines, and just wait until there's someone you can walk up to, like in the World Showcase. If he loves Epcot already, then it may be easier to sneak in characters there, instead of in the Magic Kingdom that he already doesn't like.
Or if the Fairies are absolutely necessary, then hit Toon Town right at Rope Drop, so your wait is shorter.
You can't make him more excited about it. If he had never been before, then maybe, but he's already waited in those lines, and KNOWS he doesn't enjoy it.
Also, if you only do 2 Park Days, which parks do you do? Maybe you could do a couple extra days in the parks. That way you just spend the low crowd mornings there, then head back to the hotel for some rest and other activities.