A/N: I wrote this in January for a prompt of James and Sirius as friends. Please let me know what you think about it.
James and Sirius sat in the small room of the church James was going to be marrying Lily Evans in shortly. Sirius was dressed in a nice suit and helping James to get ready. "You know, Prongs, no one actually thought you'd be marrying Lily." James smacked him and then adjusted his tie for the hundredth time. "I forgot to mention that I'm glad we were all wrong." Sirius added on, hoping that would help him not to be smacked again.
James continued fidgeting with his tie until Sirius had had enough and decided it was his turn to be hit. "Stop it, it looks fine."
"Are you sure?" James looked into the mirror again.
"I'm sure." James really did look incredible in his suit.
"Please be appropriate with your toast. I don't want her family getting upset."
Sirius feigned indignation. "You act like I can't restrain myself. I'm hurt, Prongs."
Lily was late getting to the church, so they had time to kill. They sat on the sofa reminiscing when James asked Sirius if he ever thought he'd get married.
"I'm too busy being a rebel. You were supposed to be my wing-man, Prongs. How could you do this to me? Think of all the heart attacks we could have given Moony with our shenanigans."
"We can still have fun, Sirius. I'm getting married, I'm not dying." He ran his fingers through his hair again and resisted the urge to look in the mirror again.
"Ah, but marriage changes things. For once I'm completely serious, all jokes aside."
Silence fell again. Sirius could tell that James was nervous, and it was his job as best mate to distract him. "So is it against the rules to get drunk and snog Lily's sister, or would that be considered not restraining myself?" He smirked.
"That's disgusting and I think Moony would hit you."
"Good thing I've got some morals and don't go for married women." His joke had worked in distracting James. A knock at the door told them that it was time to start the ceremony. James started to walk out of the room when Sirius stopped him. "Wait, Prongs." He furrowed his brow in deep concentration, trying to think of the proper way of wording things. This is why he needed Moony, he thought. "You're gonna be fine. You and Lily are perfect for each other, and I'm honestly happy for you both." He smiled. "Let's go get you married."