Jo wants to join us

Jo hesitates for just a moment, her eyes darting between my face and my still-hard cock. Then she lets Penny guide her onto the bed beside me.

"Don't be nervous, baby sister," Penny whispers, kissing Jo's cheek. "Daddy knows how to make it feel really good."

I reach out and stroke Jo's hair, marveling at how perfect she looks in this moment. "You're so beautiful, Jo," I tell her. "But we don't have to do anything you don't want to."

Jo bites her lip, then looks up at me with those big eyes. "I want to," she says softly. "I've always wondered what it would be like."

Penny giggles. "She's been watching us through the keyhole, Daddy. Haven't you, Jo?"

Jo blushes deeply. "Only once," she admits.

I pull Jo closer, feeling her soft skin against mine. "Well then, I guess I should make it worth watching, shouldn't I?"

I lean down and kiss her, more gently than I had with Penny earlier. Jo's lips are soft and uncertain at first, but soon she's kissing me back with surprising passion. Her small hands come up to touch my chest, exploring the muscles there.

Penny watches us for a moment, then climbs onto the bed behind Jo. She begins kissing her sister's neck, her hands cupping Jo's small breasts.

"Oh!" Jo gasps against my mouth as Penny pinches her nipples.

"Does that feel good?" I ask, breaking our kiss.

"Yes," Jo whispers, her eyes half-closed.

Penny smiles at me over Jo's shoulder.