Ten Commandments

I was looking at something on Pintrest which was "The Ten Commandments for Children."  And for the "Do not commit adultery" one, it said "Be faithful in marriage."  However, I really think that's simplifying it.  Does that mean that single people can do whatever they want?  No consequences?  I think that if we're going to be fair to our children (and to their future spouses), we should probably teach that commandment as "Be faithful to your spouse."  And when the child says "But I don't have a spouse," we can reply by asking, "But do you plan to have one someday?"  If they say "yes," then they can start being faithful now.  "Do you think that spouse would like you ________?"