He would say missionary because he wants to watch Remus’s face or hear him whine into his neck. His legs would be so tightly wrapped around Remus’s back, pulling him closer and closer and closer even though there was no space between them. Remus would have Sirius’s hands over his head, fingers interlocked against the mattress, in a way that was so intimate. He liked feeling close to Remus. All the praise, soft moans, quiet “I love you,”s. He liked to feel so loved and taken care of.

But he would also 100% be into doggy. Remus got possessive near the full moon, and Sirius loved to tease him and get him all jealous. He loved how wild he got, chasing his own pleasure instead of Sirius’s. He loved the way Remus would slide a hand down his back and smack his ass every time Sirius would thrust backwards into him. He loved the degradation, being told what a slut he is with his head being pushed farther into the pillow. He liked being used.

He would also mention being on top and riding Remus into oblivion. Remus wouldn’t take long to turn into a whimpering mess under him. He would tease him, embarrass him, turn him into a blushing mess. Remus would try covering his face, but Sirius would take his hands away and plant them firmly on his hips, maybe even along his stomach. “Don’t be shy, baby,” he would say, “I feel you all the way here. Can you feel yourself in my stomach, moony?” Just as Remus was so close to his finish, Sirius would slow down, lean against his chest, and grind slowly on his dick. Mouthing along his throat, whispering just about the naughtiest things he could imagine. Sirius loves watching Remus take down his guard. He loves to take care of him.

To dom in? definitely mating press or doggy

To sub in? probably cowgirl/reverse cowgirl or some freaky bondage shit

But my OVERALL favourite has gotta be missionary, it's vanilla but you just can't beat it.

Thank you for the ask anon! xx