At first this will be out of your control, and it also depends on what you consider the "end" of sex. Is it your orgasm, is it his? That will vary greatly by partner and the mood each of you are in. But sex doesn't have finish with his orgasm or yours or eithers. "Sex" can continue by cuddling, showering, making out and getting excited again and doing it again. Don't judge sex by time, do it by enjoyment.
Quote from MangoEmily: “Having to wear that seems annoying but I'm told it's so you don't get bullied for your clothes which is probably good. All my parents care about is that I wear 'real' pants so it's a lot of jeans and hoodies currently. ” what do they consider 'unreal' pants?