A contest or fight involving womens breasts. There are several variations including Hands On, No Hands, and Titboxing. In Hands on, the women place their hands on their opponents breasts and squeeze until one submits. In no hands, the women use only their tits to fight, either bumping breasts, simply mashing together, or bearhugging until one submits. Titboxing is a variant of no hands except that there is no use of the arms at all either for leverage or bearhugging.
Two women are interested in determining which has the best breasts. They decide to determine which is the best with a no hands titfight. They battle until one or the other submits and admits her opponent has the best chest.
A term used for topless photos sent by a girl to a guy who would then forward the photos to all his bros via cellphone. Usually associated with frequent Myspace flirting, and often used as a simple one-worded question as a text.
Bob: Bro you have to check what this myspace chick sent me
John: Those are titpics if I've ever seen them!