It's established in that Sirius, James Potter, and Wormtail became animagi to watch over Lupin when he "wolfs out", knowing that he's not a danger to animals in that state; Sirius changes into a large black dog, the animal out of the three who would most easily to calm down the werewolf Lupin. ) Tonks is only a metamorphomagus (she can only change aspects of her human appearance to that of another human), her shapeshifting power wouldn't be of much use against a lycanthrope Lupin.
Now, remember that Regulus actually died at age 18 trying to kill a Horcrux.
Starring Remus, Tonks and Sirius, supported ably by other Order members, risque dialogues and bad-arse jokes. Due to faulty Contraceptive Potion, someone finds herself knocked up, and her significant other wants to "make an honest woman out of her." Unfortunately, there are several major obstacles between them and the altar.
Two-days-earlier prequel to "Wardens of Wizardkind." Headmistress Granger has some ideas for modernizing the school's curriculum.
-Joe32 , ("You're going to suffer..you're going to be happy about it") is meant to foreshadow this. There are plenty of romantic and sexual subtext in Sirius' and Remus' relationship in the books to make it possible.
At some point in Harry and Ginny's relationship, Ginny will discover her inner dominatrix and Harry will embrace his submissive side. There's Lupin's staunch refusal at first to accept Nymphadora Tonks' affections for him because she possibly couldn't handle him during the full moon (despite being an Auror).