That's Nate Archibald and Jenny Humphrey MAKING OUT!
I know they kissed once last season but that was an accident and then after that they were just friends - but you know, only when the writers remembered and Jenny needed him to unwittingly help her out-Heather Blair. Now they're making out?
Why isn't this show on 5 days a week?
On a side note - Chace Crawford is 23, Taylor Momsen is 15, so this is vaguely pedephilic.
And I really like her bag.