He wants the royal pussy

"Can I fuck your pussy?" Bran asked bluntly, to horny to be subtle.

"Ohhhhh no," Jaime interjected, shaking his head, "No way I'm letting some kid fuck my sister's pussy. If we're doing this, which I can't believe we fucking are, it's gonna have to be another hole."

Cersei looked ready to argue, but just shook her head. "Fine. Sorry, but I guess my pussy's off limits. "

Bran was disappointed, but decided not to push his luck, considering Jaime Lannister was the Kingslayer. It's not a good idea to argue with the Kingslayer.