I agree with you for the most part if not entirely. It isn't for everyone but if it works for them then why not? I've been with couples like this a few times. I haven't been involved in a group thing like this but I've been in a few 3somes with couples. For whatever reason it has always been my guiltiest pleasure and I've been fortunate enough to have met up with a couple looking to spice things up a bit for them.