as you grow up and mature and stop being motived by your desire to impress others, you start to learn self control and realise that sex is simply vigorous exercise with a happy ending.
How good it is depends on the person you are doing it with, a lot of "10s" simply have no idea what to do and are shit at sex.
I have been with my partner 20 years and have not once thought about going through with sex with another woman, sure I look at women and find them attractive , but as far as having sex with them in real life, whats the point?
Why upset your current partner, as Jove said, if you are thinking about having sex with another woman, the one you are with isnt the one for you, break up and move on.