Idk if this has been round tumblr yet, but how do we think Regulus would react to finding out about the "prank" that Sirius pulled on Remus in fifth year.
Already dating moonwater.
Remus is going to Regulus as soon as he can walk again, sobbing the hardest he ever has, inconsolable really. He has to get talked down from multiple panic attacks before he can even get a rough explanation out of what James had told him had happened, who at the time was shaking so badly from poorly concealed rage at Sirius.
But Sirius better count his days. If he isn't already disowned by now, he will be shortly because Regulus will stop at nothing to make his life a living hell until Remus and Sirius have made up on their own terms. He is beyond livid and manages to turn most of the school against Sirius when they don't even know what happened (like Harry's 4th year but worse)