According to Sirius, bribing Remus to do anything was the easiest thing in the world. To effectively bribe him, the only thing needed was to mention any sweet he loved. And with the right amount of sweets, he could get him to do anything he wanted. 

The most common occasions on which Sirius would be bribing Rem were when he needed him to do his homework, or write an essay, help him with subjects like Ancient Runes, History of Magic and Arithmancy or just wanted him to keep him company.

***

Sirius: "Would you come over at my place?"

Remus: "No."

Sirius (resuming as if he hadn't heard Rem's refusal): "Because I have just bought your favorite chocolate cake."

Remus: "I'm sorry to disappoint you but me and Lily were planning to go to a bakery to get some cake for Harry. So either way I'm getting chocolate cake, thank you."

Sirius (trying to tempt him further): "I stocked up on Godiva bars as well."

Remus (pausing): "Oh... I hadn't known that."

Sirius (raising his eyebrow suggestively): "Along with a big box of biscuits..."

Remus (narrowing his eyes at him): "Hey, are you bribing me?"

Sirius: "Exactly. Is it working? Or shall I increase the bribe?"

Remus (stuck in a catch 22 situation): "But what am I going to say to Lily? She said we had to go this evening."

Sirius (shrugging as if it was no big deal at all): "Tell you what, go with her to the bakery first and have your cake, then come over. Double treat. And I'm Sirius about this." 

Remus (shaking his head as a smile crept up to his face): "of course you are."