Honestly Kaveh's birthday letter last year with the new detail of him and Alhaitham trying/sharing coffee is one of my favorite facts, even more so because it's canon.

I'd like to imagine them traveling together, trying coffee in new cities or countries, and they always take a few bags of various flavors back with them to enjoy later on. Alhaitham probably even spoils Kaveh further by importing some of those same coffee beans again in the future, especially if Kaveh was really fond of them.

But just the simple fact that every day they wake up and have a cup of coffee together is such a domestic scene in and of itself. The gentle conversations they have over their coffee coupled with affectionate touches and comfortable smiles, all of it is so lovely.