And The Punchline Is “and The Nurse Says ‘i Heard You Tell The Other Guy”" What Is The Joke?

there is an old man in a nursing home, he goes up to an old lady “i bet you can’t guess my age”
“73?”
“nope, i’m 92″ he goes up to another, “i bet you can’t guess my age”
“81″
“nope, i’m 92″ so he goes up to an old man “i bet you can’t guess my age”
“77?”
“nope, i’m 92″ so he goes up to the nurse, “i bet you can’t guess my age”
so the nurse reaches down his pants and feel all over his manly parts
“you’re 92″
“thats amazing, how in the world did you figure that out?”
“i heard you tell that other guy”…
the joke works a little better if its a lady in the home with him instead of a nurse in my opinion