Starsky walks into the bathroom as Hutch is steping out of the shower.
Looking at Hutch's penis and balls, he says, "Damn, Hutch. I wish I was as... uh, as en..uhhh...as big as you are"
Hutch, blushing bright red but figuring he'll have some fun, replies, "To make that wish come true, you have to rub oil into yourself everyday. Takes about three weeks or so, before you see any difference, though."
About a month later the same scene repeats. This time Starsky complains he's been following the regimen, but with no change in his size.
"What kind of oil are you using?" asks the secretly, very amused Hutch.
"Crisco," says Starsky. "Ya know, from that great big can you gave me as a gag gift after I was shot."
Hutch, hand on his chin, thoughtful expression on his face, says, "Well, buddy, I think I know what your problem is; ya see, you're using shortening......"