I was just drunk enough to think, "What the hell?" and told her ok. Walking was just as hard as I thought it would be. We had to go very slowly to keep from falling. After a little while we got in step with each other and managed to say upright. It was fun in a way; though I could not see anything at all. There was almost no light from the back but a tiny bit drifting down from the head my sister was wearing.
She would reach out and hug her friends and I would flap the big wings popping them in peoples' faces, asses or whatever was in the way. The effect the teasing and the walking with my crotch pressed tightly against her ass was having on me caused my cock to twitch and grow. "No!" I thought to myself sternly, "I can not get a hard on with my cock pressed against my sisters ass."
I tried to think of everything gross and disgusting in an effort to keep my cock from raising its head but between the teasing sexy voices I heard and my sister's ass going up and down as she walked, my cock rose and there way no way I could stop it.
I knew she felt it but it did not seem to bother her. The more she walked the more her ass slipped up and down my cock. It was almost like being jacked off with a huge hand. We were getting so hot that sweat was running over both of us and it only acted like lubricant. I was getting more and more turned on and there was no way I could deny it. Ideas were rushing through my mind.
Was it the feeling of having my cock worked or the fact it was my sisters ass that had me so turned on? It hurt my head to think about it and I wanted to just go with the feeling. I want to cum. I needed to cum. At times it seemed she would bend over further to hug someone and her ass cheeks would wrap my hard cock even harder.
We had been walking around about 15 minutes and we were both covered in sweat. The sweat was dripping down our bodies and my boxers were soaked. I was so into feeling my sister's ass rub up and down my hard cock that I was not even paying attention to anything around me. I was just lost in the lust of the moment.