[jcbicouple]

Dito to everyone else. Swinging is about both of you and both of you need to be comfortable and enjoying what is happening. Your wife needs to put you first: Not her lover.
Frankly, If you were both enjoying this little senerio she likes to play out it wouldn't be a big deal, but you aren't enjoying it. Therefore it's no longer something you're doing together; It's her going out with some guy and leaving you home. You two need to talk and and re-establish comfort levels. If she isn't willing to do that, and blames you for anything: We'd suggest stopping everything to do with swinging (or going out to have sex with her "friend") all together!