In Japan cousin-romance is not considered to be incestuous, so I don't think they were doing it to go for an edgy/pervy theme.
Maybe you weren't trying to be funny, but I almost cracked up in the middle of a dead silent computer lab. Thanks.
OT:
Sudden, vague endings. Maybe trying to be artsy / mysterious, but in reality it's just a giant plot cliff. i.e Elfen Lied.