"The elephant's trunk transplant" joke

Jack goes to the doctor and says "Doc I'm having trouble getting my
penis erect, can you help me?"
After a complete examination the doctor tells Jack, "Well the
problem with you is that the muscles around the base of your penis
are damaged. There's really nothing I can do for you except if
you're willing to try an experimental treatment."
Jack asks sadly, "What is this treatment?" "Well," the doctor
explains, "what we would do is take the muscles from the trunk of a
baby elephant and implant them in your penis."
Jack thinks about it silently then says, "Well the thought of going
through life without ever having sex again is too much, lets go for
it."
A few weeks after the operation Jack was given the green light to
use his improved equipment. He planned a romantic evening for his
girl friend and took her to one of the nicest restaurants in the
city. In the middle of dinner he felt a stirring between his legs
that continued to the point of being uncomfortable.
To release the pressure Jack unzipped his fly. His penis immediately
sprung from his pants, went to the top of the table, grabbed a
dinner roll and then returned to his pants.
His girl friend was stunned at first but then said with a sly smile,
"That was incredible! Can you do that again?"
Jack replied, "Well, I guess so, but I'm not sure I can fit another
dinner roll up my ass!"