Never heard of tweener before I thought of it. Maybe I did. I don't even watch pro rasslin, so how I heard of it, I have no idea. :P
(from the jeremy jargon file
Someone who is split between different hobbies or professions, usually ones that conflict in nature. This can even include personalities, but not to the extent of something like DID, as most tweeners are as such knowingly and willingly.
Tweeners can usually be spotted by other tweeners, because of similar characterisitcs, such as methods in speech and prose. Tweeners can range from someone who is completely silent about their plurality, to blatantly open about it. Most will fall somewhere in between, occasionally perking up or saying things that would alert other tweeners to their presence.