Flour covered kitchen
Remus arrives a couple of minutes later. While Regulus waits for him to arrive, he makes sure to throw away his abomination-cake. No need for anyone to see that thing.
The door opens and Remus’ voice cuts through the silence, “I’m almost disappointed there’s no fire” to which Regulus rolls his eyes.
“Why hello to you too, Remus.” He says as Remus enters the kitchen. The taller man just smiles and waves. The bastard. He’s lucky Regulus likes him.
Remus glances around the kitchen as if looking to see if he’s going to get a glimpse at the so-called cake but gives it up quickly enough when he realizes Regulus made sure to be rid of it. “Right. Well, what kind of cake did you want to bake?”
To which Regulus explains his vision for a birthday cake for his boyfriend, and Remus nods. There are a few more questions about whether or not Regulus has a recipe already (he does), if he has all ingredients (also a yes). Regulus hands Remus the recipe and the older reads it through.
Soon Remus turns the oven on and explains in a bit more detailed way than the recipe what Regulus should do to help. They get to baking, and after an hour or so an edible looking cake sits in front of the both of them. Regulus is almost proud over himself. He's covered in flour, and so is his entire kitchen, but there is a not horrible looking cake in front of him and he's willing to count his wins.
Remus smiles "Well, there you go. Do you need help decorating it?" Regulus shakes his head as an answer. He can handle that much. Probably.