Using "trap" to describe an otokonoko character (such as that bird) is the quickest way to get the cold shoulder from any trans friends you might have or could make. To that community it evokes the specter and fears of trans panic hate crimes. If one isn't familiar, those are crimes of violence perpetrated against trans people when their birth sex is revealed to someone who was prior attracted to them. Sadly many aren't as openhearted as Oshido.
we could discuss whether he is actually a trap, since he honestly didn't know his gender, but that would be pointless, since the whole chapter was built solely for the MENdarin duck pun...