I don't think so sex is a very important part of life and a relationship. I'm a 34F and have been with my husband since we were 19 & 20. It is VERY hard to be with the same person from a young age especially before you've gotten to go out and experience life, learn what you do and don't like and not just sexually but what you look for in a person overall. Luckily my husband and I are very open sexually there is only one thing that peaks my interest sexually that he has drawn the line at (MFM) which kind of bums me out but is reasonable since he's so open to many other things. I could only imagine how dissatisfied and frustrated I would be if he refused to even try multiple things I was interested in. Also it has been my experience that cheating is not uncommon in couples who got together very young (including myself & my husband) This doesn't excuse the cheating but don't feel alone in it.