Dark (yandere???) Severus but he's more secretive about it- like I can imagine him being the type to like be very 'normal' about Lily and James (he acts like he hates him) but turn around and literally will hide in the dark corners of hogwarts and start acting crazy about them, like he will literally be hugging himself while trembling and biting his lip about them and literally acting like a desperate mutt-
I also like to add that he would definitely be the type to like have one of their clothes and just hold it close and nuzzle into it only to be disgusted by himself- (he gets comfort from there smell and from anything of theirs may that be touch, smell, seeing or hearing them) so I can imagine him spiraling when the 'prank' happens because first he almost died, second one of his crushes saved his life but is friends with the one who almost killed him so boo, thrid off his other crush is ignoring him after he lost control of his feelings and called her a mudblood- like he differently was going crazy, and I can imagine the other slytherins weren't helping because they most likely act the same (yes I'm doing the 'yandere!slytherin' shit) so I can see some of them comforting him while others say he had it coming for liking Lily and James-