Interesting thread with a lot of great ideas.
Let's see, how would I like to be punished by a girl. I would want it to be embarrassing, uncomfortable, and a little bit painful. Of course if I'm choosing the punishment I would want it to be arousing for me, too. :)
I would want the girl to invite a few of her close friends to join her. Perhaps 2 or 3 female friends and even 1 male friend. They would all take a comfortable seat and I would be commanded to stand (still fully clothed) in the middle of the room in front of all of them. I would then be commanded to strip completely while all of them watched. Once I was stripped, I would stand before them, legs spread apart and my hands up behind my head. They would all be allowed to get up and take a much closer look at my body.
Next, the girl would tie my hands behind my back to prevent me from resisting or struggling during the remainder of the punishment. A fairly large butt plug would be produced, which I would be forced to lubricate as it is shoved in and out of my mouth. After adding a more substantial lubricant, the girl would order me to bend over in front of her and would slowly insert the butt plug into my waiting rectum. She would continue to tease me with it, barely inserting it and then withdrawing it, until she finally had it inserted all the way. As I stood before them, the girl would now attach some type of CBT device, perhaps just a cock ring or leather cock strap, or maybe a ball separator or something similar.
Assuming that the girl was actually my girlfriend, she would want to embarrass me by making me watch her with another man. That's why her male friend was invited. While I stood before everyone, she would kneel before him and give him a blowjob. Of course as I watch this scene, I begin to become excited myself. Once her male friend is satisfied, he turns his attention to me (it seems that he likes to play with boys as well as girls). He approaches me and slowly starts to jack off my now rock-hard cock. He brings me almost to the point of orgasm, but then stops short of that -- frustrating me. He repeats this several times, never letting me experience a full release, but just making my cock harder and me more frustrated.
It's now time for a paddling, so my hands are released from behind me as I am commanded to bend over. My hands are now fastened to my ankles, forcing me to stay bent over before the group. The girl produces a wooden paddle, and she now begins to use it on my exposed ass. After she punishes me with it, the other women in the audience are invited to take their turn with the paddle.
After being paddled, I'm ordered to kneel before the group and my hands are once again tied behind my back. The girl now approaches me and removes her jeans and panties. Turning around in front of me, she bends over and exposes her anus to me. I'm commanded to lean into her and lick her, stimulating her anus with my tongue. Several of the other women take turns doing the same thing to me. Her male friend now approaches me, unzips the fly of his jeans and pulls down his underwear. He forces his erect cock into my open mouth, forcing me to suck him off. As he ejaculates, I'm commanded to swallow every bit of it in order to avoid further punishment.