These two look friendly. I presumed they are roommates, so they comfortable sharing food and clothes. It’s just some roommates need to be reeducated on proper lines and questions not to crossed&asked.

If the shock of my suggestion gets in, e may be able to retrospect:

Wait, why am I asking to to indirectly kiss my roommate from the drink e is drinking from?

The idea is that the askee can get es own drink, and only wants permission.

Our canteen rules are extremely simple: take whatever you want, but replace it ASAP. That way nobody gets to miss out on their favourites.