Every single bit of the advert will have been well thought out and is there for a reason. They have deliberately leaned into the possible problem father, abuse etc with the nervous kids, glances, a son that felt he couldn’t speak to his father etc. It’s sick really but that’s marketing, they’ll do anything to be talked about.
Again, its all open to interpretation. Im ot seeing a possible problem father or abuse etc it could be integrated in loads of different ways. Maybe an argument on Christmas morning is causing tension. .maybe its his step dad and its the first time he's called him 'dad' and he was nervous about doing so.
Maybe kid has come out gay and dad needed to process.
Literally anything coukd make up a back story.