I do think Chris is actually bisexual, albeit more attracted to women than to men. He did have an aversion to men for a long while, most likely because of the sketchy shit that happened with the principal (and whatever inspired the JenkinsJinkies story), which probably overrode any attraction he had. I think at this point though, he's literally just too mentally unwell for that aversion to continue, so now he's able to feel attracted to men.
Aside from that he seems to have very few aversions in terms of sex if Barb, Jessica Quinn, Sonichu 8, and saying he'd fuck a Corgi are anything to go by. It does seem like foot fetishes (Sockness) and vore fetishes (that one art contest entry) are a turn-off for him, at least.
In terms of his own kinks, the most commonly recurring themes are glasses, belly dancing, sex toys, and humiliation. Oh, and mothering, of course.