So everybody should just sleep with everybody that they love? One biq happy orqy?
Do you see any potential problems with that?
I personally do not profess to claim sufficient knowledge and wisdom to dictate to others what they should or should not do behind closed doors in private.
Is it my business to do so?
Was this a private or a public setting that you witnessed this behavior? (If I may be permitted to presume you did not participate?) If you did not witness the behavior, how do you come to know of it? If it is purely hypothetical, why should it concern you (or me) (or anyone else)?