You were left alone with her

You watched in confusion as Caitlin walked out the front door and left you alone with her sister. Was Caitlin just being sarcastic? Did you just ruin a wonderful relationship with her?

"Let's go to my room. We don't have to worry about Caitlin, but our parents could be back any time", Dana says. You followed her sheepishly, the bra still hanging in your hand. At leastDana was being serious. If you were going to throw your relationship under the bus, it would go out with a bang.

Dana's old room was still in the same condition it was left in when she left to study in another town. There was a small bed and a writing desk, the kind of furnishing you'd expect from a high school student's room. Dana sat on the bed. You grabbed a feel of her breasts. You couldn't believe the amazing weight of them, yet they felt a lot firmer than you had expected. You felt Dana's hand search for your erect cock through the fabric of your shorts. "Take it out. Do what you want with me", Dana whispered. You dropped your shorts to your ankles and guided your hard cock between Dana's G cups which her already at the perfect height for you. Caitlin's D cups are just about big enough so you've done your share of titty fucking with her, but this was a totally different game. With Caitlin, you would have to help with your hand to keep your cock from popping out of the cleavage. Now, your cock was firmly embedded in the soft cleavage of Dana, who was pushing her tits together for you. You started moving very carefully, fearing you'd blow your load instantly. You noticed Dana's breathing become heavier as you gently titty fucked her.

"Jeez, John, you finally took a hint. You know how many times I've pictured you like this when rubbing one out...", Dana whispered. You pulled your cock out from her cleavage, as hearing this almost sent you over the edge. "What? You've been masturbating to me?", you asked her dumbfounded. "Yeah, I've practically had to do it every time I've seen you", she said. "What?", you said a second time. "That makes two of us. Do you think this would have been the first time I had to masturbate in your parents' toilet?"

"What? So my flirting did have an effect on you?", Dana said. "Flirting? That was flirting? I thought you were just being fucking oblivious about how much skin you've been showing! That's the worst flirting I've even seen!" "I don't know, I don't usually flirt! I hate when men ogle at me. Well, other men", Dana said.

You paused for a moment, absorbing how stupid it seems you two have been cluelessly masturbating to each other for years. Finally Dana broke the silence: "Come on, John, fuck me! I need to know what a cock feel inside me!" Hang on, she said "a cock", not "your cock". "What, is this... is this your first time?", you asked her dumbfounded. "Yes, but never mind about that. Just do what you want to do", Dana said. "Do you have a condom?", you asked her? "A condom? No, screw that, just fuck me, fuck me already", Dana begged.

You guided Dana on her back on her old bed and remove her bikini bottom. You found her wet hairy pussy and guided your rock hard member inside. Dana's old bed creaked horribly as you rocked back and forth violently. The realization of the situation - fucking your girlfriend's virgin sister with huge boobs hit you in less than a minute and you started throbbing and releasing inside Dana.

You pulled out and prepared to meet a disappointed face for you lasting such a short time. But instead Dana smiled and said "Thank you, thank you, thank you... You made me feel like a real woman. Now get dressed and get out of my room before my parents catch us. I'll finish on my own". You got dressed and closed to door behind you. You heard Dana's muffled moans through the door. You went to pack your bags in case you needed to make a quick exit when Caitlin would return.

Couple of minutes later, you heard the door go. It was Caitlin. She disappeared into Dana's room for a while. She then came to meet you. You were surprised to see she wasn't the least bit angry. "Good job, quickshot!", Caitlin grinned at you. "At least you popped her cherry, and I don't need to listen to my sister whining about being a virgin anymore. Just try to last a bit longer the next time, okay? Yeah, yeah, she told me all about it. I love my sister, even when she's being a cunt. Maybe she'll be less of a cunt now that I borrow you to her."