A couple of minutes later, I watched as Karen gently guided Donna back up so the two of them could exchange a number of kisses before Karen began her own oral explorations.
There were a couple of times that I had to remind myself to breathe as I watched Karen return the pleasures she'd gotten from her older sister, and get the same results. I could only watch, fascinated, as Karen brought Donna to the same level of arousal as herself.
The last thing I wanted to do just then was disturb them in any way — it was simply too amazing to watch how they were with each other, and witness two such lovely young women giving each other pleasure. I just sat there in Donna's chair, not daring to move for fear of breaking the spell that was developing between them. Even as the contents of my pants was growing, so was the love that I felt for them in my heart; the depth of their obvious love and affection for each other only made me love them that much more.
Eventually, Donna patiently guided her sister upright again, and the two of them once again shared several soft and loving kisses before they moved to lay down. I found myself holding my breath as I watched Donna move over her sister, and slowly kiss her way down Karen's body while Karen raised her knees and opened her legs in anticipation of where the older girl was headed. I knew when Donna made contact with Karen's sex by the way Karen's hips lifted off the bed, accompanied by her deep moan of pleasure. As much as I wanted to be able to see exactly what Donna was doing (so I could learn to do it, too!), I was loathe to risk any noise or movement that might distract or disturb them. Instead, I had to sit as patiently as I could, watching and listening as Donna applied herself toward pleasuring her sister while Karen played with her own breasts.
I don't think that Donna tried to do anything to slow down or speed up how soon Karen climaxed; she simply seemed to want to make her sister feel good, and tried to make it happen -
which it did a few minutes later when I saw Karen freeze for a couple of seconds before releasing a deep groan of pleasure. Donna appeared to find the taste of her sibling as enjoyable as I did, because she apparently kept her tongue and/or lips busy even as Karen spasmed several more times. Only when the younger girl was laying there gasping did Donna lift her head from between Karen's thighs; after licking her lips, she moved to lay over her sister. When Karen had gotten her breathing under control, she didn't hesitate to pull Donna's head down for a kiss that quickly escalated to the two of them trying to lick each others tonsils before it ended.
Karen then wrapped her arms around Donna, and rolled the two of them over so that Donna was on her back on the bed; from there, Karen soon had her lips fastened on one of Donna's breasts.
When she let it slip from between her lips, I could see that Karen had brought Donna's areola and nipple to lovely shiny points; she then proceeded to perform the same service to the other.
Then it was time for her to work her way down Donna's body — except that instead of simply kissing her older sister, Karen was softly licking, and using her lips to bite the surface of Donna's belly, then abdomen. Donna, too, lifted her knees and opened herself to her sister, and welcomed the first contact of Karen's tongue on her womanhood. I think that it took a little longer before Donna had her own orgasm, but I can't be sure — the truth of the matter is that I was so engrossed with watching them that I completely lost any sense of time. What I do know is that Karen didn't bother licking her lips; she went straight to getting herself over Donna, and the two of them once again quickly progressed from a brief, gentle kiss to their tongues dueling in each others mouths. Only after that kiss ended, and they'd shared a couple tamer ones, did they seem to remember that they'd had an audience.
First Karen, then Donna, looked over at me — plainly waiting to see what my reaction would be to what I'd seen. It took me only a moment to tell them "That was the sexiest, most lovely thing I think I'll ever see. It was obvious how much you love each other, and that you were both trying to make the other one happy. Thank you, both of you, for letting me watch that."
From the expressions on their faces, I knew that I'd not only reassured them that what they were doing was okay, but that I'd pleased them by letting them know that they'd pleased me.
It was Karen that told me "It would be okay with me if you wanted to get naked and get in bed with us, Uncle Ted.", quickly followed by Donna's assurance "Me, too!"
It was invitation enough for me to stand up and start shedding my clothes. Both girls were amused when there was a brief struggle (har!) as I tried to get my shorts past my erection; once I'd accomplished that, I was laying next to them in a matter of just a couple of seconds.
A little bashfully, Donna said "Karen told me that she gave you her virginity. If… if it's okay, I'd like to see… you know, what it looks like when you're having sex."
I looked at Karen, and with minute nod of her head, she let me know that she was agreeable -
leaving the final decision up to me. I'll confess to being a little intimidated at the idea of being watched while I had sex; but I was also more than a little aroused by it, too. It took only a moment for me to answer "If you want to watch, then it's okay with me… you can even help get both of us ready, if you want."
When Donna looked at her, Karen told her "It's easier for him to get inside me if both of us are wet — like with saliva."
That was all Donna needed to hear, and she quickly told Karen "Why don't you lay on HIM, then, so I can do both of you?"
Karen smiled, and was soon laying on top of me, straddling my hips; a few seconds later, Donna was kneeling between my thighs. She proved to be an excellent "helper" — she was more than willing to get Karen aroused again while keeping ME stimulated along the way.
When Karen was ready (well after I was!), she raised herself over me and started to reach between us. Before she could get her hand on my erection, I heard Donna tentatively ask "Can I hold him for you? So I can see what it's like from the beginning?"
Karen didn't say anything, and just pulled her hand back; a moment later, I felt Donna's cool hand wrapped around me. I felt Donna take the head of my cock in her mouth for a few seconds, the pull her head back, followed by her telling Karen "Okay, you can go now — I just made sure he's wet, too…"
Smiling down at me, Karen lifted herself enough for Donna to get me into position at the entrance to her vagina. Slowly, knowing that Donna was watching, Karen began to lower herself onto me. Her arousal, and the coating of saliva that Donna had left on me, made it fairly easy for Karen to get the head of my erection through the tight ring of her opening — accompanied by Donna's gasp at watching it happen. When Karen had settled herself onto me far enough, I felt Donna release her grip on my erect penis; but she never moved from where she was, watching as more and more of my manhood disappeared into her younger sister. Only when the last of my penis had disappeared into Karen did Donna say anything; even then, all I heard was a soft "Oh, god, that was so sexy!"
Karen held herself still on me for a few seconds, then slowly lifted herself up again so that Donna could see what it looked like when my penis was sliding back out; both of us smiled when we heard Donna's soft moan of arousal — plainly, she'd found the sight as exciting as we had.
Donna stayed between my legs as Karen gradually increased her movements on my cock; though she didn't make any more comments or noise, I was fully aware that she was there, just as I'm sure Karen was. As stimulating as it was for me to know that Donna was watching Karen slide herself up and down my manhood, I know that it had an even greater impact on Karen, who was easily as warm and wet inside as she'd ever been when she was alone with me, and moving herself farther on my cock than she usually did. She was also more responsive to my touches on her breasts, and ass, and body; it didn't take but a few minutes for her to have her first small orgasm.