Lame Lothar rose, and his bastard brother helped him hobble from the room.

He thought of his bastard brother often, since the night that Summer had watched him ride off through the storm.

His bastard brother Jon was there now, a man of the Night's Watch.

He put a hand on Bran's shoulder, and Bran looked over at his bastard brother.

"Your bastard brother has all your father's graces, it would seem."

Round suggests he may have been either a uterine or even a bastard brother.

You have no direct kin in Nhi, bastard brother: only me.

I have to give you due credit, bastard brother: you were good.

Sansa's own oh-so-honorable father had given her a bastard brother.

"Obviously she prefers my company to that bastard brother of yours."