Our experience is limited. We had a good couple friend of ourse with whom we used to party quite a bit. Till one day we got quite drunk and someone (honestly we dont remember who) suggested some cross-mating. It was fun. We remained friends and never did repeat that again, for some reason.
I had similar questions about my wife. She seemed to enjoy it a lot more than me till I also decided to join. After the initial surprise, everything went well. Anyway, we have never tried that with single guys again.