Okay, so the chewing gum tag made that kind of obvious. Yeah, that was one of the things in my bathroom. The gross part is that our trash can isn't far from the toilet - that wad of gum wanted to jump over and land on my leg. I just know it did.
On to the "issue".
I'm not 100% sure where it stems from. I think several bad experiences - gum in my hair when I was a kid - several times. I'm trying to come up with a definitive and I can't. It's the smell, mostly, and the way it sticks to places it shouldn't be - probably just an accumulative type issue with roots in places I've forgotten - except for the smells.
I will chew gum on occasion - not often because it makes my jaw hurt. I'm not freaky enough that I forbid it in my house. I did for a while, but that was mainly because I would constantly find spent gum in odd places. Now that the kids are older and at least respect my weirdness, it's okay. As long as they keep in in their mouths and make sure it makes it into the trash can.
Maybe just not the bathroom trash can.
A non-exciting issue. To be sure.