those yohipharian boys...
Although, in their native culture, Park would be considered their third gender, identified by the phenotype called "yen". It's perfectly normal for yen to become involved with yan yohi, so I'm not sure if in their native culture if it'd be considered gay...
BUT Park was not raised on his home planet and was instead raised in a mixed-culture setting and doesn't necessarily identify with his species' cultural ideas about gender and instead identifies more with the traditional binary male.

I like developing cultural stuff but hey I'm an anthropologist.

Also they are v cute.