I believe it was a TV movie about a divorced man who had a son and a daughter. Both preteens or young teens. He takes his kids to Europe someplace to meet his new girlfriend who also has a young daughter. The man’s kids are opposed to their fathers relationship so they decide to go on a hunger strike. The woman’s daughter agrees to join them. But then the woman’s daughter and the man’s son start to form a relationship and the man’s daughter catches her brother buying food for the woman’s daughter and the kids start fighting over this. I don’t remember how it ends or what happens next or if I even saw the rest of the movie but I’ve always wondered what happened that’s why I’m trying to find the movie.
Sounds like it could be “The Battle of the Villa Fiorita”. Here’s the imbd link for it: https://www.imdb.com/title/tt0058949/?ref_=nm_flmg_act_57