First, you must understand that her brattiness is part of the game, and not a problem to be fixed.
Most people are very well-behaved: they spend their whole lives being polite, respectful and courteous. But when they’re in private, with their most intimate acquaintances, they want to express a different side of themselves.
They want to be transgressive, they want to challenge the rules they’ve spent their entire lives studiously obeying. They want to push the boundaries, knowing full well there might be painful consequences beyond.
That’s why spanking is such a popular fetish. In my experience intelligent, ordinarily well-behaved ladies love fantasising about being naughty for once, and the prospect of someone strict holding them to account makes their panties wet.
Perhaps your partner likes to struggle, talk to her about what she desires. Perhaps she fantasises about being tied up, and being rendered helpless. Or for someone strict to see through her bratty little games and properly take control of her chaotic mind.
Likewise, if she’s struggling because she actually doens’t like being spanked. Then stop. Just because you’re sexually dominant does not earn you any special privileges. Her preferences are just as valid as yours.
Always remember that kinky sex is just adult play. It is not forcing your desires on your partner, it’s about transforming another human being’s deepest desires into something that brings pleasure to you both.
Understand her, and align with what she needs.
Play your role.