No, daddy wants you to use your hand

"No, baby," your stepdad answers. "I want you to use your hand and I want you to watch."

"I get it," you grin. "Like in science class. Like an experiment."

"Yes, honey," he chuckles. "Like in science. Make my volcano erupt."

You reply with a girlish giggle. You slide so you are lying on your stomach between his legs. You prop yourself up on your elbows, a position that gives you a good close view of his slippery cock and gives him a nice view of your big tits squeezing out of your shirt. You adjust your grip on him, tightening your hold and positioning your hand so your thumb drags up the skin of his shaft into a bunch beneath his slippery cockhead on each upward stroke.

"Like that?" You ask.

"Yeah," he groans, "that's real nice, sweetie."

You snuggle even closer to him so you can get a really good look at his cock. You stroke his thigh and then slide your hand down and between his legs to massage his balls. Your fist works firmly and persistently up and down his cock. Whenever a droplet of precum forms at the hole you glide your thumb over his cockhead and spread the lubrication down to his shaft. In no time your stroking fist is making a juicy sound with each up and down pump.

"Does it feel good, daddy?" You ask.

"Ohhhh," he moans, "it feels real good. You're going to make daddy cum real soon."

"Like a volcano?" You ask in a chipper tone.

"Like a volcano," he chuckles.

You add a twist of the wrist to your up and down stroke. The precum you are using to lubricate his cock is being frothed into a line of white foam on the top of your hand. Your stepdad is jerking and groaning and beginning to hump his cock against your fist. Sweat beads on your forehead and your upper lip from the effort and your arm begins to grow sore, but you are relentless and steady in your pace. You intend to jack your stepdad off until he spews his load.

"Ohhhh yeah," your stepfather begins to moan repeatedly. "Ohhh yeah."

You watch him watching you, your gaze flicking between his increasingly contorted expression of pleasure and the deepening red of his slippery dick.

"Fuck," he gasps, "Don't stop! Don't stop!"

"Are you going to cum for me, daddy?" You ask.

He answers with a strangled cry of release. His whole body stiffens and you actually feel his cock throb in your grip. Once, twice, and then with a gasp of pleasure the purple head of his cock erupts. The first explosion spews almost straight up, a thick white gob trailing a rope that flies up above your head and then splashes down across your arm, his leg, and the bed. His cock spurts out jets of semen that coat your fist in his warm and sticky fluid.

"Oh, sweetie," he gasps with a dumb grin on his face. "You are such a good girl."

By the time he's finished cumming it is quite a mess, but you don't hesitate to take charge of the cleanup.

"Really, daddy?" You ask and then dip your mouth to his cock and begin licking up all of his salty spunk.

It's not an unpleasant taste, and he seems to enjoy the show you put on, licking and sucking all over his thighs, balls, and cock until the only liquid on him is your saliva. By the time you're done he is hard again and you can see by the gleam in his eye that he is eager for more.