Not sure how to handle this one

There's a couple that my bf and I have played with (once) at an on premise club (bf knew them in vanilla world before me). It was fine...hot, but neither of us were WOW about it but we do like them. The only real issue is she's not totally bi and I am, she will only make out with a chick or pillow princess it. They have been swinging for years, so their thing is she likes single guys and he likes single girls and they both like couples, yet allow each other a ton of freedom with their preferences. Here's the issue: this Saturday he's going to be at the club where we've all played before but with his single "girlfriend" while wife is out of town and he wants to play again. Wife knows about his plans, but part of me (us) feels weird about her not being there. Am I overthinking it?