A gentleman handsome came in 'cross the transom

...

"So remember your mothers and sisters and lovers,
And let her sleep under the bar
..............be-side-the-ginnnnnnnnnnnn."

Last line in typical barbershop close harmony of course.

It's in Songs for Swingin' Housemothers as Her Mother Never Told Her with alternate listing in the index as Let Her Sleep Under the Bar.

I don't have it handy to check, but I believe that in "the other book" titled Song Fest it was called The Lady in Red.

Lyrics for the "gentleman handsome" vs "gentleman dapper" are quite variable, according to recollection, with transom, phone booth, crapper, and a couple of others for what he came through/over/across/past/out of/'round etc.

Military versions may have even more variation than the college/outing club/mountaineer versions.

John