I never had that problem. My teenage son has always wanted to play piano-going into music next year at college. But the other kids only wish they wanted to play it. I did tell them that I want them each to choose an instrument or singing to work on, because music can do SO MUCH for them and us.
Maybe your sons would be interested in another instrument. You can usually get instruments at pawn shops so it doesn’t always have to cost a fortune to try another one.
Our philosophy has been to never make the kids play an instrument they don’t want to play, but the others are a lot younger than my teen. They haven’t picked their instruments yet. My 11 year old agonizes about what she wants, my 8 year old sings all day long, and my 7 year old is still in his own world, but he gets out the guitar and sings the blue sometimes. Pretty funny.
We have always had music of different kinds in the home, and I think that helps too.
I know a lot of people though, that say they’re glad their mom made them stick with piano. I’m interested in what others think about this too.