If I cant go over my friends house and have boyfriend and the only way to visit him is over her hou?

if i'm geting this right. i think his sister doesn't want you and him being together. but she shouldn't have authority over that. if his parents don't mind then she needs to accept you being his girlfriend. that's up to his parents not his sister.

well, maby they just know what boys and girl of your age like to do! They were there to and they did the same so their not stupid even though we think so lol. Go to them and ask them if thats why they dont want you to and if thats the reason tell them to trust you.