Have a Brony boyfriend? Does it bother you?

Brony: A name typically given to the male viewers/fans (whether they are straight, gay, bisexual, etc.) of the My Little Pony show or franchise. They typically do not give in to the hype that males aren't allowed to enjoy things that may be intended for females.Other spellings: Bronie
Taken from urbandictionary.com
I personally believe that any person should be able watch any show they enjoy without criticism. In fact I even supported my boyfriend when he told me he liked the show and we've watched together! (It is very cute and we both enjoyed it). But then he just slowly started growing out of it, watching it less, its been almost a year now since hes watched the cartoon, till yesterday that is...
I was fine with him liking the show till yesterday, now its really bothering me and I'll tell you why.
We were cuddling in bed watching Youtube videos, it had been around an hour already of just going from random video to the next, we weren't doing anything sexual in any way at the time. Then we came across a My Little Pony, cute, well-done, parody video. He started watching the show intently.... And a minute in he got an erection that lasted past the end of the 8 minute show. 
He got an erection because of cute childrens cartoon ponies.... Thats whats bothering me
Im just curious if my feeling are shared with  anyone else? Would you be bothered that if after an hour of cuddling with your boyfriend the thing that gave him a big erectiom was My Little Pony?
Would it bother you that of all possible videos to give him an erection it was a cute, childs cartoon?
In my own head I compare it to, what if I told you watching spongebob got me all hot and bothered? (It doesnt.) But wouldnt that creep a few people out?