I would think part of the allure of meeting someone new is the unknown, the exploring, the affirmation or changing of fantasys. But, if someone has a much smaller than average vagina or much larger than normal penis, there ought to be some warning to prevent harm and major dissapointments, though.
I have a friend with what would definitely be called a porno penis and he finally had to get to the point of showing it to the ladys first and asking them if they were sure they could take it as most couldn't. BTW, he's a very skinny white guy, go figure.
While I don't have what I would call a "porno penis" I have been keeping discriminating women happy for quite a while now. About half my FBs complain that it makes them sore for a day or two afterwards, but they keep coming back.
Does anyone ever ask anyone how large or small their vagina is? I think if I was at a meet and greet and began being asked exactly as to size and such I would just end the meet right there. But, everyone has their reasons for doing what they do and I can't fault them. We all have a few questions that have to be asked at a meet and greet, that is part of what they are for.
I would hope anybody that has been having sex with various partners, much less swinging for a while has learned to think on their feet (or back or knees), be flexible, and imaginative enough to always make sure their play partner experiences the most possible pleasure.
Have you tried any SMs that have been in the lifestyle for awhile. You don't stay in the lifestyle as a SM very long if you don't have the tools and the talent to get the job done. And remember, in the vanilla or swing world, a hung man is like a beautiful woman. Irregardless of their personality or marital status they pretty much have their choice of partners and anyone wanting their time will have to take a number. If you make it to the head of the line and don't meet their criteria, it's "no soup for you"!