He's a literal baby and such a cinnamon roll, that my dear friends, is a fact. He's so shy at first he can't even come near you and talk to you but oh, how his heart ACHES and LONGS for being close to you and wanting to be with you and talk to you about stuff

You'll have to approach him on your own lol since he'll never approach you on his own. Bby boi here is far too insecure and his head is filled with insecure and negative thoughts about what if he screws up the first impression with you and does something so bad that you'll hate him forever? He can't have that happening, his fragile little heart won't be able to take it, he'll be really sad. And he definitely doesn't want to accidentally make you think he's some sort of werewolf freak and hate him for the rest of his life for it, that would just crush him. So, he'll resort to keeping his feelings at bay by just watching and observing you quietly and being content with just that

However his dear pals, Sirius, James and Peter would sooner or later come to know about his crush on you and after all the teasing and stuff, they'll help him get close to you. You know your friends try increasing and boosting your confidence and help you get ready whenever you're about to meet your crush but they always do something or the other to 'accidentally' get you closer to together like pushing you closer to them and stuff? Yeah.... that's what these boneheads here will be doing lol

After much pestering and encouraging from his friends, he thinks he's mentally prepared for this and the second you turn around to look at him it's all over for him and James and Sirius would literally be facepalming as he stutters getting lost in your beautiful eyes and drowning in the beauty of your wonderful features. All he can manage after days of preparation for making a first impression with you is a 'Hi'. A faint one that too, with his face red as a tomato and he rushes off somewhere to calm his erratic heartbeat. He thinks now you hate him and you might think he's some sort of weirdo but on the contrary, you actually think he was cute

He has books filled with your likes and dislikes and he knows it's no normal to have information about you like this. And sometimes he also follows you around just to know if you're safe or not, and of course, the other Marauders would be encouraging him with his yandere behavior for you

He knows his feelings for you are completely wrong and irrational and he should get rid of them immediately. After a while he'll start ignoring you to try burying the feelings deep down but he just can't forget the feelings he has for you. Such feelings of deep possessiveness and want for you.... he can't seem to get rid of it and when you feel sad and upset that he's ignoring you, that's when he'll stop since he doesn't want to see you sad ever. Seeing you sad or upset about something is the last thing he ever wants, poor bby boi's heart will get crushed if he sees tears in your eyes

And when you do find out at some point or the other that he's a werewolf, he'll panic and he'll tell you to go somewhere far away from him so he can't hurt you. But you chose to stay with him and even in his werewolf form he won't ever hurt you, he's gained that amount of self control, you're too precious for him. And he won't ever kidnap you for something stupid like talking to other people and not paying him any attention, he'll only kidnap you if he feels you're safety is being threatened. He might be a lot of things but he's also really paranoid about your safety, he can't afford to lose you. So, he'll hide you in the Shrieking Shack till he passes out of Hogwarts and then he'll take you to some other place with him, and of course, the Shrieking Shack will have all sorts of enchantments and advanced hexes you can't break. He'll of course have his friends helping him when it comes down to all this

He understands what he did was really wrong and begs you for forgiveness and that he just wants a chance to prove his love for you. He'll even kill himself for you, he loves you so much please don't leave him. He'll shower you with so much love, never raise his hand or voice at you, treat you with the utmost respect and care you'll eventually fall in love with him on your own. Of course part of him feels guilty that you're falling in love with him in these types of circumstances but there's another selfish part of him telling him that it's okay to be selfish once in a while and just relish and enjoy the moment so in conclusion, one of the BEST yanderes to have :)