What you think you know about Stiles is all wrong. You see what really happened that night was a little different than what appears to have happened.
Scott and Stiles went out into the woods that night to look for half of the body. Scott got bit, but what happened after Scott wasn't aware of. Stiles went back after his dad, Noah the Sheriff, took him to his Jeep, Roscoe, found Scott's inhaler and the other half of the body.
Stiles gets bitten, but not in the same spot as Scott (neither are aware the other got bit) (ps Scott got bit on the side of his abdomen) he got bit on the wrist.
Will Stiles tell Scott he got bit?
Will Scott tell Stiles he got bit?
What will happen to them?
Read more and find out. Let the curiosity be sated because curiosity killed the cat, but satisfaction brought it back.