She hates the marks at first.
The angry red lines etched into her skin from the claws of a dragon so eager to mark her territory. They make her feel cheap. Like there's yet another over-entitled royal who thinks her body is their property, and if only she didn't make Regina quake with pleasure every time she made said marks, the Queen would demand she stop.
But the Dragon ignites a fire in Regina that she didn't think possible - has never felt before, and each etch she tattoos in her skin, each time her claws draw blood, Regina decides in some far off corner of her mind that it's worth it.
Maleficent's need to press patterns into her skin is worth the pain it comes with. Worth the extra inconvenience of finding another excuse to hide her body from the King because with those marks, with each scratch she leaves behind, ugly and red against the silky smoothness of Regina's skin, comes the only bit of light left in her miserable existence.
It comes with passion, with dancing tongues and lips that suck her skin, ones that leave yet more marks on her body in the form of small bruises and rigid teeth marks. It comes with the type of life Regina has never had before, the kind of pleasure she's only ever dreamed of feeling in the forgotten life she'd mapped out with a stable boy so long ago.
It's in the dead of night she realises she's wrong. When she's still twitching and left shaking as her blood pulses around her body, lying naked in the fur throws draped over the Dragons's bed, one offhand comment on the part of Maleficent that makes the young Queen realise she doesn't do it to claim stake on her body. She doesn't do it because she thinks Regina belongs to her.
"Has he seen the nail marks?" She asks, and what else can Regina say but yes? Of course he has seen the marks the blonde leaves behind, as a souvenir of their dalliances. A smirk flits across the older witch's lips, and she pushes her fingers into Regina's hair. Presses a sweet kiss to her lips.
"Good. At least he knows-"
"At least he knows I'm yours?" Regina bites, snaps, suddenly angry and unable to swallow it down that she's made herself belong to someone other than herself once again.
Maleficent's hand drops. "I don't leave those marks for me, dear. I leave them for him."
That's when the penny drops.
Maleficent doesn't use her claws as a means to stake claim. She uses them to show the King that she's doing something he will never be able to.
After then she finds she doesn't hate the marks quite so much.