It's the difference between male protagonists from different anime and their own female protagonists.
There are no cups, only washing utensils!
There are love letters (letters) to express the youth between the male protagonist and the female protagonist, their own thoughts, feelings for each other, etc.
There are also some ambiguous scenes between CPs (different male protagonists and female protagonists) that I wrote. They are meat-eating, sometimes clean water, there are kissing scenes, ambiguity, and a touch of warmth.
If you want to write a book (especially if you are a fan), you can refer to it. In a sense, the male protagonists of different anime are matched with the attitudes, character descriptions and analysis of the female protagonists with different personalities.
You can also nominate, that is, tell me which anime you want to have the male protagonist and what kind of character the female protagonist is, and then write it in a love letter to let you know what kind of reaction and attitude the male protagonist will have.