This is something that Ted and I have a LOT of experience in

...not the traditional DP (anal/vaginal)...but vaginal DP.
We had played this game for years with just a dildo, and once we started talking about actually doing in it in real life we never really thought that we would ever find a man who would be comfortable with it.
While chatting with a single man that we were going to meet for a threesome we were discussing some things we would like to try. I mentioned that a vaginal DP was on our wish list and he said he had done it before and was willing to do it again...we did

and I was hooked big time (this was very, very early in our swinging journey).
Since then I have become extremely vocal in what I enjoy in a MFM threesome, basically no holds barred (I used to be very shy about what I wanted

)...and when we are chatting with a single man I ALWAYS let him know that this is something I want and that if he is too uncomfortable it's really no big deal, there are numerous other things to do, but....I have NOT been turned down yet.
Maybe we have been lucky, but we do strive to make our single men feel comfortable and through chatting feel them out so see if they have any homophobic tendencies. If/when we come a across one that does, we let them know that we probably are not the couple for them as our threesomes tend to be extremely wild and even if a DP is not done that night, some of the other positions and things we like, do require very, very close contact from the males. So if a man is homophobic in the slightlest and can't let himself go to enjoy the moment, regardless of what it might bring, he isn't for us.
Teresa