What do you do if your certain but your parents don't like your relationship?

Perspective taking. This is difficult for you and for your parents. If we give them the benefit of the doubt, and begin with the perspective that their desire is to protect you, a good starting point would be to have a heart to heart talk with them about their concerns. Ask them and try to look at your relationship through their eyes. You may find they have valid points, and the discussion may bring you closer.
Pause. If you love your parents let them speak their concerns. Even if you think they're being unreasonable, listen with respect and assume they want the best for you. If it is agreeable with your philosophy, pray about it. Take your time. Excitement is not productive.