Lol very random question. I'm sure it doesn't make you gay. Your friend could just look like a woman. But that's besides the point.
I'm glad she responded positively. You became an alpha and took control of the situation by releasing that Tension you both had. Now you can do the teasing you have already started doing and keep it light. Have a strong intent, but do not attache to the desired outcome. Also the sister will help you avoid any oneitis. So just flirt around you don't even need to do anything with them.