My wife and I were hanging out with our married neighbour's, about 10 years older than us. We often drink together outside our houses, but tonight they came up for dinner after a few drinks. We had dinner and a few more drinks and were feeling pretty good. Throughout, the wife kept commenting about how hot we were in photos, how hot it was that I loaded the dishwasher, etc.

A few minutes later, the husband went back to their place to get more drinks, and the conversation between the wives turned to how often in a week they had sex. A moment after that, my wife went upstairs to change, and the conversation between the neighbour's wife and I continued. It then turned to asking each other if we'd ever had a threesome and I said I wish. She then revealed that they'd had a 4some about 10 years earlier. I expressed that I loved the idea of that and asked if she'd ever want to do with us. She said totally!

Unfortunately a minute later, I had to take a call that I couldn't miss, and they left while I was on the phone (it was a long call).

Barring the phone call, what should I have done to try and make that 4some happen?