Updated: How would you tell them

So I am 20 my SO is 37. My parents think I am dating a 29 year old that has a daughter. He is really 37 with 4 kids and currently in the middle of his second divorce and I am in the middle of my first. How would you tell your parents the person they think I am dating and they know makes me happy is a lot older and has more kids than they thought. Oh and not to mention when I first tried to tell my mom about him she freaked out and told me I was dumb to date someone that has now been divorced twice. Help!

Well they officially know I told my mom Friday and my dad yesterday they were both upset but have told me they love me I am their family and they support me in the choices I make. My SO are currently preparing to move in to am apartment together and that will like happen before the new year. Thank you for all the advice it was scary but I am glad they know!