Raised very conservative by a hypocrite

Amanda • Just existing until further notice
So growing up my mom n dad preached about not living with someone until you are married and when I was younger I agreed I wouldn't. As I got older I found out that not only did my mom live with my biological father before they were married but that they were having sex too an I was possibly conceived just days before their wedding .. And that my granny and papaw lived together and would have never gotten married had it not been for my brother being born... Well I have found the one I want to spend the rest of my life with and we want to get a place when I graduate college in November .. My parents and granny are going to freak out.. Isn't this hypocritical ? I know I know they mean well or they don't want me to make the same mistake.. Yada yada yada .. I'm 26 I should be able to make my own choices .. Anyone else from the same background? How did you tell them? How did they cope? Did yall get to move past it? Please help bc I am doing this but I don't want to burn bridges with my family