twfun,
This is your fantasy world and you have the right to do this.
I ran into another scenario a couple of months back. I have had a great lay and was sheepishly returning home when I ran into a girl in the street, she was really fantastic and decide to bone her too. Took her to a love hotel and ol faithful was ready at full mast to do an encore
. Banged till kingdom come and the rooster started crowing, but no juice flowed
. That was the most selfless act I had committed.
So to correct your fantasy, as mine. I would have to say that my testicle sack needs to be as big as a donkeys, with performance to match ones irrational exuberance, on demand.
I am sure the shaft would hold up, after all this is a muscle