Never forget GoT turned "not rape" into rape more than once, this being one of the first times.
Another being when Joffrey is lying dead in the tomb and Cersei is so stricken with grief she basically mounts Jaime the second he appears on the page. Not actually that unusual a behaviour for those who suddenly face the death of someone close, even less unusual when it's a mother who has just lost a child and the father appears next to her. That biological urge to replace the now dead investment is stronger than people want to admit.
In the show however Jaime not only instigates but Cersei is actively against it. At first.
Never forget GoT turned "not rape" into rape more than once, this being one of the first times.
Another being when Joffrey is lying dead in the tomb and Cersei is so stricken with grief she basically mounts Jaime the second he appears on the page. Not actually that unusual a behaviour for those who suddenly face the death of someone close, even less unusual when it's a mother who has just lost a child and the father appears next to her. That biological urge to replace the now dead investment is stronger than people want to admit.
In the show however Jaime not only instigates but Cersei is actively against it. At first.