Overheard by our daughter having a conversation about sex

A private conversation between my wife and me was overheard by our teen daughter this morning, and I’m not sure what to do next.

After returning from the gym, in the garage after getting out of the car, my wife mentioned that she was feeling better (she had been ill this week), and that we should make time for sex later. She said “if I’m not up to it, I’ll help you out at least.” I said that her timing was great because seeing her in her swimsuit at the gym gave me a huge urge to go down on her, if she’s up for that. She gave me a smile and raised her eyebrows, but then…

…she realized our teen daughter was standing behind me. She had heard it all - she was in the garage and we didn’t realize it.

I pretended (or hoped) she hadn’t heard anything, but my wife says she clearly did.

I don’t know if we should talk to our daughter about what she heard, or just leave it alone. Ugh.