When the wife and I are meeting a guy for the first time for a M F M threesome we always meet at a local Hotel where there is a quiet beer garden, we have signs worked out and if he is OK to both of us then we invite him home for fun and games.
We have never had a problem with it.
Swinger clubs, meet and greets and open places are good for meets.
You should also discuss expectations before the meet as sometimes people may come off as forcefull purely because they have the wrong idea.