I think I'm a little confused as to what you are asking. Are you asking for permission to have sex with a person whom you've already had sex with? Are you wanting to ask your parents to let you have sex in their house because you now consider yourselves married?

It seems like you were able to be alone for a few hours, the sexual tension was too much, you decided to spiritually give yourselves to one another (intercourse), and now you are trying to relieve some guilt about this action by saying it's ok because it's what you believed all along.

I assume you are over the age of 18 since you are both in college. You are now adults and should be able to do what you want. True, you have to respect your parents and not behave inappropriately in their presence/house, but what is it the two of you really want?