User blog comment:Paul.rea/Teen Wolf Novel: Chapter One/@comment-66.87.2.155-20120719054642/@comment-217.84.44.45-20120831223349

yes,in S1 Allison steals a condom from her aunt and in episode 5 they have a conversation that heavily implies that they plan on sleeping together that night (they then remember the teacher conference and get caught by their parents but they must have hooked up sometime between that and S2s 'Restraint' in which Scotts mother finds an almost empty condom pack.

Scott "saying" that they didn't have sex in 'Restraint' means absolutely nothing as he's saying that to Allison's mother (and Allison's family doesn't hunt down and kill Scott on the sole condition that he's not dating Allison).