The stepsister likes to swallow his cum

The boy gets up at night to get a glass of water and the stepsister grabs his cock and kisses him very horny. She jerks his cock and gives him a blowjob in the kitchen until the boy fucks her on the counter. They are both very horny and are at risk of being caught at any moment but they need to fuck until she swallows the boy's semen. Whenever they can they end up fucking and they know that no one in the family would understand