The Effects of Oysters

I swear. My life isn't normally this eventful. About a year ago, receiving a letter in the mail qualified as a moment to celebrate. Nowadays, strange stuff happens more frequently. Not sure if it's in the air.

A couple of weeks ago I was at an after-work function with some former co-workers. The bar we were at featured a free oyster bar. It was the first time that this particular crowd had seen me in a social setting. So needless to say, I was more relaxed and less PC. I was also very excited about getting free oysters. Nothing improper was said or done. I wasn't drinking. So nothing that happened that night prepared me for what happened next.

This morning I received an email at work from one of these former co-workers. He wanted to know if the oysters had their desired effect on me that night, and wanted to know if I wanted to get together to [insert euphemism here].

I was floored. This guy is married and has two small children. I'm not sure how to respond to this email. The way it's worded could easily be construed as a very inappropriate joke or as a very serious proposition. This guy and I have always had a jokey, flirtatious relationship, but this was completely uncalled for.

Any advice? I'm sitting on this email for a bit until I can figure out a polite yet tasteful response.