He won the fight, so her life is his now. This is medieval times or you kill or you fuck.
She is basically his slave now, so why can't he do whatever he wants?
It's like in GoT... every single episode someone died, in the worst possible ways... there was even a pregnant girl that was stabed in the belly, but that was ok, just fine...
Incest was ok too... sex next to your child corpse was great, a reason to fap...
But then there was a rape scene, after 5 seasons of immorality... "OMG we should just shut down this show!"... Fantastic.