When my Brother Cums Over

My brother came to me saying, "My wife won't do this. She says I can't just go to anyone to get it, but she trusts you." The thing he wanted was intense glans rubbing. I have no idea what it is for him. I mean, what does he get out of it? But he enjoys it so much, I do it. I've tried the same thing on my husband, and he doesn't care for it at all. My brother will come over. I'll get him naked on my bed. Sometimes my husband hangs around and talks with us, watching, sometimes even sitting in the chair next to the bed and stroking his lovely cock. Sometimes he's at work or just downstairs watching TV. Sometimes, when I'm in a particularly horny mood, I'll get naked too, but not usually. So my brother is laying there with his dick already erect. I'll tie him to the bed. It's easy enough to do. I've got these soft rope-like things. Each wrist and ankle is tied to the headboard and tailboard. My husband and I never realized when we bought that bed, but it is perfect for tying people down. One time, my husband tied me down, and started jamming ever larger cucumbers into my puss. Boy was that something! I've seldom had orgasms like that. I want him to try fisting me someday, but that's another story. This is about my brother. So, typically, I'll have him tied down, and I just grab his erect cock in one hand, and start rubbing the oiled palm of my other hand over the tip. He yells, he squirms, he pulls against the ropes, but to no avail. He seems to be in some sort of intense tickle, I can't really tell. He has a safeword, but he never uses it. This glans rubbing thing is kind of unique. It seems to give him super intensity, but is absolutely harmless. I know there are people who experiment with pain or intensity in sex, but take risks, like sticking themselves with pins and needles, or jamming large things into themselves (like me with the fucking cucumbers), but I like this because it's harmless. Well, mostly harmless. One of the first times we did it, I didn't use any lubricant. I rubbed the tip of his penis raw. It formed a scab and took several days to heal. No permanent damage, but still! As soon as we started to use lubricant, the problem went entirely away. More than that, he says the feeling is actually even more intense with the lubricant. And, even though it's my brother, I get super-horny doing it. Or, maybe not always so horny, sometimes it's a milder kind of joy. I just enjoy helping him out. I mean, I really like that. Go figure! Does he ejaculate? Hell yes, most times, right in the middle of the process. Just for fun, I'll keep going after he has cum, with the stuff still all over his cock and my hands, and he'll squirm and yell twice as badly. He'll stay hard for quite a while in that post-orgasmic state. Finally, his penis softens up. Then I know the fun is over. He'll also do more than ejaculate sometimes. We keep a plastic layer under the first sheet, because every now and then, he'll just cut loose, and involuntarily pee all over the place. Usually, it's just a trickle that suddenly squirts out, but sometimes, he just can't stop the flow. I just keep on rubbing, with the pee squirting out against my palm. That's it. Nothing more, other than it makes my husband and me terribly horny at times after my brother cums over, and we get on that bed and have a great time of our own. A couple of times, he and I have rolled around in the cold, wet sperm left behind by my brother, which I find terribly sexy.