What would you do if you just discovered that your mutual loves song that you despise and you have bad memory with that song... I know it's not a problem theoretically but how to explain this to myself. I'm sorry. I just that song makes me violent.

I wouldn’t listen to the song and I would add all versions of it’s name to my blocklist of course.

Additionally if there isn’t anything inherently wrong or immoral with the song itself or whatever then I see no problem with my mutual enjoying it.

I guess I’ll just avoid interacting with them when something has to do with music, if I’m really paranoid.

Of course, if likeing the song has moral or ethical implications/concerns then it’s a different story.