Dee railed him hard everytime.
Of course that's what Dennis wanted. What he craved. He wouldn't let her do it if he didn't want it. Hell, she wouldn't want it unless he put the idea in her first.
So what if he had to take the day off or show up late to conceal the fact that he was sore, if any of them could actually notice. So what if, momentarily, for a night, Dee could delude herself into thinking she was in control.
It appeared that she was in control. To the trained eye. She was fucking him with a strap on dildo and whispering or screaming insults and degrading, filthy words as he gasped and moaned and uttered meek replies.
However, he was the one in control. The one that had the power. Dee's feeble womens-bird brain could never have discovered her kink for pegging without him to guide her.
Ok it's true. Nowadays he doesn't always choose when she pegs him. Sometimes she says, "On your knees" or "Bend over" or "suck my cock" and yes he would comply, rock fucking hard and with a smile on his face. But he could turn the tables at any time.
He often did. He'd fuck her hard sometimes, gentle othertimes. Sometimes he'd choke her as he fucked her. The look in her eyes...always got him though. Sometimes she'd look terrified, tears in her eyes, tearing up as he choked her. Other times she'd look defiant. An expression that read "Kill me you bitch, if you fucking can."
Other times they looked loving. An unfamiliar expression to see. It felt so real and yet like a dream. Magic come to life. It thrilled him.
He didn't like that. Didn't like that he needed that so much. He'd call her up, even nights he should have something better to do, just for a chance at that look. Weakness like that repulsed and frightened him.
Sometimes she looked...blank. Accepting. Like she really wanted him to just end her. That scared him the most. Dennis never wanted that for her. Insecurity yes. Fear yes. That ensured she'd never leave but despair? Suicidal urges. No. That's the last thing he wanted.
Dennis tried not to think too hard about that. Those nights, those looks, were getting less common now anyway.
Recently, there was a new expression when he fucked her, or when she fucked him. A new mask on her face. Laughter. Pride. Pity.
To Dennis' mind it didn't suit her at all.
Worse it was at his expense. He was being pitied, looked down on, made fun of. In an intimate moment with his sister. While he was doing what he did best. And yet she'd mock him.
If he came sooner than he expected, laughter. When she made him beg for more, she laughed. Once he hit her for it. She laughed even harder and he left and screamed into a pillow until he could barely talk the next day.
He fucking despised Dee and how she made him feel. Because he loved her and love was control.
Dennis was losing slowly and steadily his equilibrium. His balance. And he was losing his control over Dee.
Because now she knew she could control him too.