well, me and the wife both have friends of the opposite sex... and occasionally, their are dinners and lunches had with them.
what we would both have a problem with is having a meal ( non business meal) with someone the other hasn't been acquainted with.
on a couple of occasions, she has warned me that the lady I had lunches with wanted more than just lunches, and she was right... and I warned her about this particular guy friend of hers that I felt was a player, and I was right.
i didn't believe her about the lady at first...then it became evident that i had misjudged the lady and her intentions.
same with the guy friend, she thought he was just a cool dude who wanted to be friends.
we are not always the best judge of people, it's nice to have a trusted opinion outside of our own.. and who better than your spouse?
it's especially important because both me and the wife are very gregarious and flirtatious people.
we've talked about those people after we dropped them as friends, and have pretty much concluded that , if we were to have continued those friendships, we would have opened ourselves up to temptations we normally wouldn't.
if we had a bad day, maybe an argument, or we had hurt feelings, or whatever, those "friends" may have taken the opportunity to use that in order to get the friendship going in the direction they wanted.
so yeah.. we don't do dinners or other social events with people that are not known by both of us....and really, we don't do much without both of us there anyways, so it's not much of an issue anymore.