Refers to having, or having had, sex. It is a means by which lovers may unceremoniously compliment their partner, and / or their performance in general, as being an earth moving, supernatural experience. A characteristic is that one or both of the participants yells "God!" one really good time, or multiple times. If one, or both, of the participants had to bite a leather belt, themselves, or their partner to prevent yelling "God!" then that also qualifies...shoving one's face into a pillow can be debated.
"We had church last night."