Sorry for the wall of text. Just typing some stuff out that's on my mind.

So for some backstory: my buddy, his wife, my wife, and myself have all been friends since highschool. We're all extremely close and know more about each other than we probably should. They're a part of our family, so to speak.

Now, they know about my little kink as I've far outgrown the ashamed phase and don't really care. They've made one of jokes about to which I rebuttal one way or another. Again, all in good fun.

Recently, she (my buddy's wife) has been alot more flirty. We play a tabletop game regularly and she sits next to me. Recently, she's been putting her feet on my game bag and whenever I need to reach for something, she'll wiggle her toes and grin at me. Also, I've experienced some light foot-on-leg stroking. Again, accompanied by a flirty smile. She's never done this level of foot flirting before.

On to my buddy. We've had a few social gatherings recently. At the end, they stay the night. The past few, he's been.....strange. Example, he took her socks off and held her foot up at me asking "you want her foot man" or "go ahead, take it" and that sort of stuff. Very persistent. Didn't sound too joking.

Now, my wife doesn't care. We're pretty open sexually. She's said if I have sex with another woman, it's fine. She just wants to watch, get pics, or get a highly detailed story of it. God I love her.

I guess I'm looking insight or advice or just to see if anyone has had similar situations. I plan to talk with them because I'm not against it. Saying things in unclear joking ways that don't sound joking isn't ideal. I feel this requires a serious discussion, but what do y'all think?
Feel free to ask questions.