Scarlet moved cautiously as she opened the door from the inside, turned the knob to face him, and then peered through the crack to speak to him. "Just leave me alone!" She yelled and then made a move to shut the door, but Collin was quicker than her and held on to it while simultaneously pushing it open to a large extent.

Collin maintained his chastity by not engaging in sexual activity after Aubrey dumped him. It's possible that this was the reason why his animal instinct was winning out over his desire to stay away from women.

Or perhaps it's due to the fact that he and Scarlet were...