To me, if it's done safely and consensually, then it's just good fun. But, while lesbian sex is all the rage right now, the world is still not very accepting of male-gay sex.

In much of the reading I've done, even gay/bi woman are not very accepting. I read one article that took a poll of women for things in a man's past that were immediate non-starters when they were considering dating a man. The number 1 item was if he had ever had gay sex in his past.

I think as a result of attitudes like this, couples swapping in the same bed is happening but true dive-in-and-grab-whatever-you-want 4somes are pretty rare.