Calle:
Could you please either bring this back on-topic
Is there any evidence that marriage was common under Federation law?
There are a few couples that are generally referred to by fen as being married but are not in fact referred to as such on screen as far as I can recall (Vena and Muller, Tel Varon and Maja), but the only certain example I can think of is Sula and Chesku. It's a fairly common fanfic notion that marriage is reserved for the aristocracy.
Perhaps there is therefore little concept of adultery?
Tavia