I think maybe you guys just need to take a break. Everything can be fun for awhile, and after a bit it seems not-so-wonderful. I don't really think you have anything to worry about, unless you're loosing sleep over it. Or if there are any other signs that you're having serious anxiety over things. If not, I think maybe you just need to take a break, tell your wife you don't want to stop swinging, but just a recess from all the fun ;) Then talk about your limits and all.. you know, couples renew their vows to show their devotion to each other after some time has passed from their marriage... and I think open relationships need to renew their conduct code with each other from time to time.