A married friend of mine (a guy) said that he thinks 2-4 times a week is actually better than every night, just because that way there's a little more effort out of both involved... I guess it's sort of the mentality where it's still regarded as a treat, whereas any sustained stretch of every night will make it turn into more of a chore. His words, not mine. I'm just throwing them out there. Quoted for truth. Oh, and for statistical purposes, married for 18 months, in the relationship for 6+ years.