Stephen Colletti is apologizing ... "I am in your face calling you a slut," Colletti added. "That is probably the harshest moments of my life." "That is one of the worst moments of my life and ...

Kristin Cavallari and Stephen Colletti became household names as real-life high schoolers starring on Laguna Beach — but looking back on it now, they don't necessarily think that was the best idea.