Multiple orgasms

How do women orgasm multiple times? I usually will orgasm during sex because there is clit stimulation as well. However after I orgasm my clit is too sensitive and penetration becomes uncomfortable too. If I hold off on an orgasm (longer than 5-8min) so that he can go longer, penetration becomes uncomfortable anyway and then I’m not able to orgasm at all. So how can I orgasm more than once, and how long are people typically having sex?