My father learned the song when he was in a fraternity in Chicago in the late 1950's. The way he taught it to me went like this:

'Twas a cold winter's evening, the guests were all leaving.
O'Leary was closing the bar.
He turned as he said to the lady in red,
Get out, you can't stay where you are.

She wept a sad tear in her bucket of beer
As she thought of the cold night ahead.
When a gentleman dapper stepped out of the crapper
And these are the words that he said:

Her mother never told her
The things a young girl should know
About the ways of college men, and how they come and go
(Mostly go!!)
Age has stolen her beauty, and sin has left its sad scar
So remember your mothers, and sisters, boys,
And let her sleep under the bar.