So theres this boy, i think he was blonde. And he is a piano instructor. So one day, this dad hires the piano instructor to teach his sonx. The thing is, the dad has the hots for the instructor. And it seems that the son does too. They both have this beef with each other, bit they both like the same boy.

I probably got it wrong, but maybe Body Complex (dell studio)? It also has a spin-off Sex Complex