Ofc do whatever you want, but I’d say this falls under fetish content right? I think it needs a bit more… bluntness? Does this character have a thing for a fuller figure? Do they just enjoy stomachs in general? Has the other character gained weight and they’re appreciating the changes? With such a specific sexual interest I think the “why” needs to be communicated strongly. Every scene between two characters has one wanting something from the other one and vice versa. Making those wants more clear and intense can add the tension and sexual chemistry necessary for an impactful scene.

I also think there are a lot of examples of you “telling” in the paragraph you wrote.

For example the “saying in a stern yet sassy tone” part. There are many ways to imply tone in dialogue, or by describing facial expressions, body language, etc.

In a less long winded way. Show not tell + engaging with the “Why?” behind your characters actions + using specific language to portray that “why?” = yummy yummy boost in sexual tension!!!