You might observe a correlation of having more sex with your partner during and after ovulation, with breasts growing a bit in preparation for pregnancy or a period. Other than pregnancy and sexually-transmitted infections--both of which also do have other causes, today--a person doesn't change as a result of sex. Was curious why this question was asked. Also it is a fertility sign to men; a large bottom indicates to a man that a woman is fertile. Mostly the two are coincidence only.
This goes away fast though.
27 Things You Should Know Before You “Lose” Your Virginity
Do I have a weird body shape? Toxic people you should avoid in for the sake of your mental health. However, this gets better with time. Having sex does not make your butt biggerBUT having a lot of pumping against it can form it which may make it look bigger. But having sex does not always lead to pregnancy. Male masturbation is a safe and natural way to feel good, discover what gets you hot, and release built-up sexual tension.