Thanks Fun4Ds! Your posts have been some of my inspiration over time... I love how you guys have been together so long and continue to value each other.
To answer your questions...
I invited the vanilla couple on a hunch. Pure and simple.
He's a "private" guy (whenever we go on ski trips he prefers to have a private bedroom if we've got space and he strikes out on his own from time to time. A bit of a loner actually). He's also a doctor... but there's something about him that made me feel like he'd be open to it. He also has a young (26) girlfriend who's very attractive and outgoing. I tend to have pretty good instincts and just felt like he'd go. I don't think I ever considered he'd be shocked or reject it. I don't know why... like I said, just an instinct thing. Maybe I have "swinger-dar"
As for the measuring, the theme that night was "8+ inches night." I have no idea why... I asked the owners and they said it was just for fun and anyone could come. I thought it was hilarious when one of the owners handed me a dick measuring apparatus! Basically a ruler in the shape of a penis with little comments beside each measurement.
Yeah, I had a great time. I just got off the phone with my "vanilla" friend and he said he and his girlfriend want to go back... I said to just name the date.