I'm going to have a nosebleed and not clean it up
Why don't you want to clean up?
It's not the best feeling in the world to have blood all over you
I understand that you may be in a bit of pain, but you should still clean up the blood. It's pretty rude to leave it there for someone else.
Yeah, I understand. I can always take a shower and clean myself.
As you should, because it's only common courtesy to clean up after yourself especially since it's a bodily fluid. They can transmit various diseases, and it pays to be extra careful.