That's why we do it!
We actually have a rule that we
HAVE to have sex after we have played. But the rule is almost unneccesary - we are pretty much all over each other as soon as we are alone - whether that be on the car ride home or as soon as we see our friends drive away.
There was one time that seemed like a chore: we climbed into bed at 6:00 a.m. after a WILD night. We were both exhausted, but decided to "play by the rules" anyway. As I recall, that ended up being some pretty hot sex.
The bottom line for us is that swinging energizes us! And having incredible friends makes for an even more incredible "marital bed."
Spoomonkey