I guess growing up in Europe affected me... A relation built on sex, and limited by it, isn't much of one really. Spare me my own Christian rebuttal please! I think somebody truly wanting to be with somebody else, sex not being the limiting factor, is the root of the question, not getting Willy wet! One-night-stands don't end anything because they are essentially a roller coaster ride. The issue really comes in when the "stand" is made because of the root of the problem isn't right - wanting to be with the other person.
So get Willy wet if the perfect "other" has become boring. If it's deeper than that, stop thinking it's about Willy and answer the bigger question... And that goes for both people in the relationship..