One quality I look for in a romantic partner is....
The personality and humour is all that really matters to me❤
Compassion.
Ambition! If they try for the things they have or want they will try for you
I can't choose just one quality but what is most important to me is LOVE real love if he doesn't really love me he will cheat on me if he doesn't really love me he wouldn't accept if I would say he should wait with sex.
After love he should be kind and funny. 
Passion. They have to be passionate about something. It's a plus if it's something that I'm also passionate about. Passionate people make passionate lovers, and I desire deep, meaningful, almost spiritual relationships. ❤
Nice teeth shallow but true
Compassion or Humor (I know thats two but whatever). If they arent loving and funny, I cant be with them
Love
kindness <3
Trust. It is one of three traits, I think, that makes a romantic relationship strong.
@AKid65 trust