It would depend on who and why.
After rue's death she does her thank you to district 11 for giving her bread.
When a guy gets his fingers and pleasures a girl with them. (mostly put into the vagina and rubbing the clitoris)
You blow with fingers in mouth.
humm ; i can say why is keeping your fingers in your mouth / maybe he is sad or he cannot say stop .
I think a mouth stick is the thing that the doctor (or maybe dentist) puts in your mouth.
It's possible.
a mouth guard
it means your getting a hand job
"the iron man has fingers made of iron".
Wen a man fingers him self
With your mouth and fingers
Tis' actually called mouth to mouth. It is when you cannot breath and someone puts their mouth up to yours, and gives you 02, or, oxygen. Hope this helps.