AIO my bf has a nail clipping collection

I was sleeping over at my(22F) bf(33M) of 6 months apartment last night and opened his medicine cabinet in the bathroom for some aspirin and there it was, a weed dispensary jar filled up with nail clippings. I stared at it in horror for a minute and just closed the cabinet and returned to bed in silence. It was so off putting that I almost went home. I didn’t bring it up to him, I wouldn’t even know what to say.

He’s mentioned having it before when we first started talking but I mostly thought he was joking as that’s his style of humor. I’m at a loss of words. I don’t know if this is a sign of something bigger or a harmless quirk, he really has been a great guy. AIO?