Edward Furlong (child star from Terminator 2) hooked up with his 29-30 year old tutor when he was 15:
Their relationship lasted for 5 years, and they got married at some point. Apparently, his mother freaked out over this combination, and tried taking things to the courts.
I remember watching him on Regis and Kathy Lee, many years back, while the "child" star was promoting something. I can't remember really but...I think Kathy Lee said something like...."Yer so cute...do you have a girlfriend?" And he was being a badass and all like, "Ya...I got a girlfriend...She's 30 years old and she is my babysitter."
He had this big smile on his face, and started cracking up...and I guess found it hilarious when Kathy Lee responded with horror and disgust.