Lindsay Lohan had a good reason for dumping that greasy couch-monkey Riley Giles - she was having sex with Heath Ledger.
Radar Online says Lohan texted Ledger to set up a liaison while the two happened to both be in New York over the Thanksgiving holiday. Lohan's rep Leslie Sloane Zelnick refuted the story however, saying:
This is gross. She and Heath are friends.
Ledger, for his part, has not been acting like a man currently involved in any kind of committed relationship. Gatecrasher had him at the Beatrice Inn Friday at 1 a.m. sizing up brunettes. Freedom is fantastic, eh Heath?
(source)