成人笑话|How strong?

An old man goes to the doctor to ask him an important^{1 question.}

Doctor, when I was^{2 in my 20's, it took3 both of my hands to push4 down my hard-on.}

When I was in my 30's, it took one hand to push down my hard-on.

When I was in my 50's, it took three fingers to push down my hard-on.

Now that I'm in my 60's, it only takes one finger to push down on my hard-on!

So what I'm basically^{5 trying to ask you is? How strong am I going6 to get?}