One of my cats just jumped in my lap and I started petting her like usual. She turned and faced away as she was getting comfortable, and I had a strong whiff of what I can only describe as acid. There's no poop smell or typical cat urine smell, and their litter box is normal. She looks like she might be a little wet in that area, but she's not dripping or anything like that. The other cat is fine, only one has this issue, and the other cat is treating her normally as though nothing is wrong.
I've looked around my apartment and there's nothing abnormal around, she didn't sit in anything. My apartment isn't very large, so I'm confident that I didn't miss anything.
What could this be? My nostrils feel like they're actually burning from the acid-like smell, it was incredibly strong.