My partner and I aren't married yet...?

But we love each other with a passion it was my idea (I'm a girl) to somehow prove our love he (boy) said we should have sex and I totally agree I've even gotten permission to well not exactly my mom said if that's what wanted then that's what I want but my dad being the big Italian he is says its shameful but he has so many different mistresses its sick so what should I do.