To the moon and back, remember ? - Wolfstar-

"what happened to us?"
"we both got caught up with our own problems."
Sirius was a casual flirt. Flirting with every girl he laid eyes on, a possible one night stand if he got lucky. (which was practically every time.) Whereas Remus was the opposite, he was a bookworm and mostly kept to himself. He didn't care if Sirius flirted with random girls but one day it finally bothered him, it made his blood boil, his heart pound quicker and his hands clammy. Sirius never really payed attention to it until one day he stopped flirting with girls completely. Shocker.