I think the question is rather one-sided. This can happen just as much with the wife as the husband. I've felt on several occasions that Mrs. WS's swing partner has gotten it better then me. In fact I've posted such on this board. But, when I look at the big picture it is because of the circumstances, not the person, that this is so.
1) There are no kids to hear us have sex.
2) There is no kids banging at the door 10 minutes after we lock it (this happened just the other day in fact).
3) When we're swinging we're not tired after a long day at work and then taking care of three kids after we get home. We're out partying.
4) When we're swinging there's no pets to care for, laundry to fold, carpets to vacuum, kids to pick-up after, dinner to cook, house to clean, neighbors that drop by unexpectedly, etc.
You know... real life stuff.
All this seems to add up to having to hurry when we have sex with each other, but when we're away from home playing with others there is no rush. There is no worry about kids hearing you scream. There is no rush to get it done because at any minute a kid will be pounding at the bedroom door.
In fact, as I write this our 4-year old is calling "Daddy, come 'ere!" and Mrs. WS is in bed with an ear ache. See what I mean... Real life.
Better go find out what the kid needs.
Mr. WS