Forced

A female friend asked me if I would like to go to a party Friday night. I hadn't been out for some time and so I agreed.
"You have to wear one of your skirts", she said.
"Oh, what sort of party is it ?"
"Not so much a party but rather just a gathering of a few friends. Don't worry, you have met a couple of them."
Come Friday night and I have on my red lace bra and matching panties and my black ankle boots when Selina walks in.
"You going dressed like that ?"
"No."
"No one would mind if you did."
"I'm not going half naked."
"I think you should wear your short grey skirt and the sleeveless grey turtle neck top."
"That would be a little revealing don't you think."
"No, I think it would be perfect for this occasion."
All I had in mind was that we were going to a party and I didn't give any thought to the phrase she used 'this occasion'.
The short grey skirt she meant was a mini and very neat fitting and showed off my butt very nicely. When I walk around in it you can't help but notice my butt.
We arrived at the 'party' and were welcomed in by the host, Frank, whom I had met before. Once inside I discovered that there were about seven or eight other people there. I was offered a drink and began talking to three other people. Barely half an hour went by when another male walked over to the group and stood next to me and said Hi with a pat on my butt.
"You look nice", he said.
"Thank you."
"I love the outfit. That skirt looks very nice or is it just your butt that looks so nice ?"
Already someone interested in my butt. I just didn't understand why all the interest, but I was about to find out.
One of the males I was talking to moved around the group to stand on the other side of me and said, "he has a beautiful arse don't you think ?"
To which the first male replied, "more than beautiful; it looks absolutely divine."
Both of them put a hand on my butt and began to lightly rub it.
"Doesn't that feel nice ?"
And the other replied, "yes, I love the feel of that wool material." I was already getting quite moist in my anal love canal from all of the attention.
A female in the group then took my drink from me and the two males took an arm each and led me over to a piece of furniture that I had seen before but didn't understand what it would be used for. I was about to find out. It was like a large cube about two meters long a meter wide and half a meter high covered in a material not unlike a pure wool blanket. I was led to one end and told to get on my knees and lay face down on the cube. Once there four people, other than the two males who led me here, began to tie my wrists and knees to anchor points near the floor of the cube. A female then placed a ball gag in my mouth. Suddenly I was becoming quite anxious about what was happening, but to late now, I wasn't going anywhere. The two males who led me here had undressed and were standing behind me, while the rest of the people stood in a semi circle around the front of me.
A pair of hands took hold of the hem of my skirt and pushed it up over my hips and then pulled my panties half way down to my knees. The next thing I felt was the head of a penis touching my anal opening.
A female voice then said, "go on Frank, fuck him."
He gave a push and the rather large head of his penis poped inside me and I moaned.
Again the female voice said, "go on Frank, it sounds like he likes it."
The penis slid all the way in and I felt very full. His hands took hold of my hips and he began to fuck me.
Again the female voice said, "fuck the bitch Frank."
"Oh, I'm going to fuck him alright. But this bitch is so tight I'm not going to last very long."
He slammed into me several times while I moaned in pleasure.
Then everyone joined in encouraging Frank to fuck me. I could only turn my head from side to side and moan, but I wasn't going anywhere.
His grip on my hips tightened and he plunged all the way into me.
"Aaarrrrgggghhh, I'm cuming, I'm cuming."
I couldn't protest as I felt his warm cum flooding into my anal love canal. I thought I was going to burst if he kept pumping. When he was finished, he slid out of me and stood back. I felt another pair of hands take hold of my hips and the head of an even bigger penis touch the opening of my love canal.
The male then said, "take the gag of him, I wnat to hear him scream while I fuck him."
A female stepped forward and removed the gag. I didn't have time to say anything before the onslaught started.  The head of his penis poped inside me and he began to push all of it into me. His penis was bigger than the first one, both in girth and length.
"Oh, he is a very tight bitch, isn't he."
"Please don't fuck me, you are way too big. You will break me."
"Too late bitch, I'm going to fuck you and I'm not leaving till I pump you full of cum."
"No, please don't."
He began to use the whole length of his penis in long, deep strokes. With each plunge I would moan loudly.
"That's right bitch, scream for daddy."
His penis was huge and I felt every stroke. I had never had a penis this big in my anus before. It was stretching me to the limit and I thought it would break me.
"Please don't fuck me, you are way too big for me. Please don't."
All of the other people started to encourage him to finish the job.
"Come on Pete. fuck the bitch. He loves it."
"No I don't. Please don't fuck me."
"He can take it Pete, fuck the bitch."
"I can't last much longer, he is such a tight bitch."
"Fuck him Pete, pump him full of cum."
"Please don't."
Just then he tightened his grip on my hips and plunged his monster penis all the way into me.
"I can't stop now, Aarrgghhhh, I'm cuming."
He stopped moving and I could feel lots of warm cum flooding into my anal canal.
"This bitch is one hell of a fuck. I could do her all over again."
He slid out of me and the whole group walked away.
I heard a voice say, "we will let him rest for a while and then we will do him again."