hotboxin'

When you and your partner have sex in a car, the windows fog up. this is hot boxin. Or when you and your friends light up a [joint] and the smoke clings to the windows.
> boy: last night i took my gal to makeout point
> friend: oh yeah! what happend
> boy: well we were getting hot and heavy but we had to stop
> friend: why?
> boy: the po-po came when the car started hot boxin