I don't even know if you are to begin with, but if you are ok with your daughter being in any kind of non-hetero romantic relationship, I don't see why you'd be mad at her for dating whatever the fuck it is you're talking about. Sure that person could get annoying, but trying to put a stop to the dating over such a matter seems counter productive. Remember when you said something along the lines of your brother doesn't let his daughter see boys, and you meant it is stupid, because your dad did the same thing to you, and you immediately got pregnant when he died? What would be stopping your daughter having the same resentment of you not liking/not letting her date a whatever gender, in the same manner your dad not allowing you to see boys didn't stop you from getting pregnant?