What is a good way to tell if a girl is bi and not a strict ?

This isn't good. You're in love with a s girlfriend and you're hoping to steal her away while living under the same roof. The best way to find out, is to get your own gf that's hot and take her home with you. If your crush has any feelings for you she'll be jealous if she doesn't have any feelings for you at all, at least you will have moved on to something you have a chance at. If you don't, this little love triangle is going to get messy and people are going to get hurt. Honestly, if they're turning you into their maid/slave boy, you pretty much know your role in the house and they're getting what they want while all you get is blue . Seriously, move on. Harsh words, but it's either that or lose her as a friend altogether and ruin what you have now. It doesn't appear from what you described that she's wanting to be with you.