Back in the 70's there was a hot topic--Open marriage--and there was lots of talk and lots of people seemed to have tried it, but ultimately it went the way--largely--of the dodo. It is like having mini affairs (and nowadays, also taking chances on some really bad stds). One supposes that since one partner partakes, the other could "sit it out" but then why bother. If you don't understand why she wants to, it does sound like your are not into this kind of playtime, and perhaps you need to not be in such a hurry to " do whatever will make her happy". That's what Clyde did for Bonnie and you know where they ended up? In any case, this forum won't give you answers though I have seen threads mentioning swinging. Only your wife can really tell why she needs to do it, the same as only you can tell your wife why you need to CD, but there is a REALLY BIG difference in the two activities.