A movie about a high school guy that moves in with/ is visiting his out of town cousins. One is a short blond girl and the other is her older brother.

The guy starts school there and notices a high school girl and wants to get her attention as a possible boyfriend. His girl cousin decides to kiss him in front of her to make her jealous, but the cousins end up liking each other instead. At the end or near the end of the movie, we find out they aren’t actually blood related.

Sometime through the movie, the older cousin shaves his head because he has “premature baldness”

I watched this a few years ago and I haven’t been able to find it since then.

Any help is appreciated! Thanks