Jem loses his britches in chapter six of To Kill a Mockingbird by Harper Lee in an incident he ends up regretting. He, Scout, and Dill go sneaking over to Boo Radley's house one night, and of course they are up to their usual shenanigans. While they do not really mean any harm, they are trespassing and almost get shot at by Nathan Radley.
As they are making a speedy escape, Jem's overalls get snagged on the fencing and he is forced to shimmy out of them and leave them behind. Jem gets in some minor trouble for not having any pants on, but he escaped punishment.
The incident could have been over then, but Jem is maturing and he does not want to disappoint his father, Atticus. Later that night, after everyone is asleep and all is dark, Jem determines to go back for his pants. He knows Atticus will be disappointed in him if Nathan Radley discovers and returns his overalls.
Scout is frightened, afraid Jem will get shot. She tells Jem the worst that can happen is a paddling from Atticus, and that is exactly what Jem is determined to avoid.
He blew out his breath patiently. “I—it’s like this, Scout,” he muttered. “Atticus ain’t ever whipped me since I can remember. I wanta keep it that way.”
This was a thought. It seemed that Atticus threatened us every other day. “You mean he’s never caught you at anything.”
“Maybe so, but—I just wanta keep it that way, Scout. We shouldn’a done that tonight, Scout.”
Even though Jem thinks Atticus is old and is disappointed that Atticus will not play in the church football league, he respects his father very much and it is obvious in this incident. He is willing to risk being shot at--certainly a true risk in this situation--just to avoid disappointing his father.