Age Difference, Please help!

Me and my SO are 12 years apart I am 17 almost 18 and he is 30. I love him so much and we have been together for awhile now, he has a kid and I am ok with that. I want to be able to be open about our relationship but I don't know how to tell my parents because they wouldn't approve. And the hard part is he is good friends with my dad.. I want them to know how happy I am but I don't know how to tell them.. 😔