I began to feel something happening along the underside of my penis, and it took me a few seconds to understand that I was getting an "outside view" of the clenching of Donna's virginal pussy as she got closer and closer to her release; knowing that she was going to orgasm with my cock in her bowels was the last straw. As I felt myself pass the point where I knew I was going to cum, I slowed my movements so that I could make my last few strokes into her as long and slow as I could so that my climax would be as strong as I could make it. The last time I pressed myself into her was just ahead of the first spray of my semen jetting out the end of my manhood.
Donna started to squeal when she felt me begin to empty myself into her, but it was cut off when her body froze with a sudden and powerful seizure that signalled the start of her own release.
Her anus became almost painfully tight around me, and the spasms of her vagina got strong enough to create some singularly pleasurable sensations along the bottom of my erection — and made my next eruption of cum nearly as strong as the first. For the next several seconds, the only things either of us could do were gasp and groan with the intensity of our climaxes.
My release tapered off just ahead of Donna's so I was barely able to keep her from falling on her face onto the bed; even then, it was a lot closer than I would have liked. Keeping myself pressed against the globes of her ass, I managed to get both of us down onto the bed, where I supported my weight with my knees and elbows so that I didn't squash her. My cock was still buried in her tight ass, and remained almost completely erect — due, I think, to the fact that her anus was still clenched so tightly around me that the blood that make me erect simply didn't have anyplace to go. That left me holding myself over her, with Donna's smooth buns pressed against my lower belly and my manhood still in the confines of her bowels while I panted to replenish the oxygen my body needed so desperately.
I'd pretty much gotten myself back together when I heard Donna softly tell me "That was way, way better than I ever even thought it could be."
"Are you okay, honey?", I asked.
She managed a small laugh before answering "No, not until tomorrow, maybe. But I don't hurt or anything."
Knowing that she wouldn't be trying to joke like that if she was in any distress, I lowered my head and softly nibbled her earlobe with my lips for a few seconds before telling her "I'm glad you're okay, sweetheart, and that it worked out the way you wanted. It felt pretty good for me, too."
"I know! I felt it when you started squirting in me, and the next thing I knew, I was having an incredible orgasm. It wasn't as strong as some I've had with you, but it felt like it was deeper, somehow. And you were an absolute dear about not hurting me, or trying to rush me while we were getting your penis in my butt — that made it so much easier for me, knowing that we were only going to go as fast as I wanted. Now you're covering me with your body, so I don't get cold or anything, and that is so sweet. I can still feel your penis in my butt, too, and I even like that."
A second later, she asked "Why is your penis still so big? Usually after you climax, it gets small again before now."
"I'm not sure, really. You want me to pull it out?"
She quickly exclaimed "No!", then realizing that I'd been teasing, she was calmer when she asked "I suppose you're going to want it back sometime, though, aren't you?"
"Yeah, I think so… I've kinda grown attached to it, and it's nice being able to use it with my pretty, sexy nieces."
"Well, this niece likes it when you use it with her, so I suppose it'll be okay if you want to keep it. But you don't have to take it out until you have to, okay?"
I nibbled her earlobe again before answering "Yes, dear.", making her laugh.
I was happy to stay with her like that for the several minutes it took before my penis had shrunk to the point that I was just barely inside her. Knowing that I was going to unplug from her any time, I asked "Do you want to clean up with me, or would you like a little time by yourself first?"
"I'd like to clean up with you, Uncle Ted. After we've done this, you don't have to worry about me being embarrassed, or anything."
A bit later, I felt myself pull free of her; after I'd gotten off of her and then stood up next to the bed, I had her roll over onto her back. She did, and I quickly got my arms under her butt and back, then picked her up and carried her into the bathroom as she snuggled into my chest. After standing her in the corner of the shower, I got the water started just as I'd done when I had showered with Karen. Once the water was warm enough, I quickly joined her under the spray; as we helped wash each other, I feigned not to notice when some of my cum dripped out of her as she was cleaning the oil from between the cheeks of her ass. Once both of us were done, I dried her off, then myself.
Once we were back in bed, Donna happily spooned against my front as I cupped her breast in my hand. As we lay there, she told me "Thanks, Uncle Ted. I wanted to find out what it was like to have sex like that, and you were so nice about helping me, and made it so easy, that I actually had an orgasm from it. I just want you to know that I really appreciate it — not just tonight, but all the times and ways you help me… and Karen and Wendy, and even Mom. We used to have kind of a hard time after Daddy left, but it's been a lot nicer and easier since you got here. I loved you more than anything, even before you came to stay with us, but but now it's even more, and better with you here with us."
I gave her a gentle hug before answering "Thank you, sweetheart. I'm glad to be here; I love all of you more than I could ever say, and I'm glad you like having me here."
She released a soft sigh of contentment, and gave my hand on her breast a tender squeeze, in response. Happy at having her in my arms, it didn't take long for me to fall asleep.
I woke up the next morning to discover that I was flat on my back, with Donna's arm and leg draped across me, and her head on my shoulder. As I lay there looking at her loveliness, I saw her eyes open. When she looked up at me and smiled, I was glad that she was happy enough about our relationship that finding herself in bed with me was enough to make her smile that way.
She started to move her leg, but quickly gave up the effort with a small noise. Knowing pretty much what the problem was, I still asked her "A little sore, this morning?"
I felt her blush slightly before she answered "Yeah — more than a little, right now. It felt good having you in me last night, but I didn't realize just how BIG you were, then. I guess you stretched me there more than I thought."
"Well, you can take some aspirin, and that'll help. I think it'll get easier if you can move around a little bit, too. It shouldn't be anywhere near as bad tomorrow morning."
"Good! I don't think I could sit on my butt all day at school if it was going to feel like this!"
I had to laugh before I told her "Come on, and take a shower with me. The hot water will make it feel better long enough for some aspirin to go to work."
She tilted her head to look at me, and smiled as she answered "I sure hope so!"
When both of us were standing next to the bed, I took her hand and she gingerly walked with me as we headed for the bathroom. As I'd promised, the hot water from the shower did relieve some of the pain she felt — particularly after she spread her ass cheeks, and we contrived to get the water running more across the affected area. She also took a couple of aspirin before we left the bathroom; once we were dressed, it was upstairs for some much-needed coffee for me, and breakfast for both of us. Teresa saw how Donna was walking, but after seeing the expression on her daughter's face, didn't have anything to say other than her usual morning greetings.