what does "take one's lumps"mean?
He didn’t like being played. He’d stand behind or in front of a cli-ent, as need be, but not when the client screwed with him.
Not when a client used him—without his knowledge or consent—to break into a house. And sure as hell not when the client roughs up a woman.
He’d have taken a tour inside Bluff House himself if the client had directed him, and he’d have taken his lumps if he’d been caught at it.
But he wouldn’t have laid hands on a woman.

Question

what does "take one's lumps"mean?
He didn’t like being played. He’d stand behind or in front of a cli-ent, as need be, but not when the client screwed with him. 
Not when a client used him—without his knowledge or consent—to break into a house. And sure as hell not when the client roughs up a woman. 
He’d have taken a tour inside Bluff House himself if the client had directed him, and he’d have taken his lumps if he’d been caught at it. 
But he wouldn’t have laid hands on a woman.

Answer

Take one's lumps is to experience difficulties as part of doing something or accepting the consequence of your actions.

Here I think it means to accept the results or receive punishment for something that he has done.