I like to keep nails in my mouth
Why would you like nails in your mouth?
I do it because it's hot for me!
Nails in your mouth seem like your thing. This will be dangerous one day, and you might swallow one. Then you will have bigger issues with needing medical attention.
Never happened. I always pull them out when the nails are tiny enough.
Even still, it's not very smart or healthy to have nails in your mouth. You should just put them in a bucket or something similar.