This song is actually "This Ae Nicht"
and the verse goes

I am the Laird o' windy wa's ("windy walls"- all outdoors)
An' I cam here wi' richt gude cause
For I hae gotten many fa's
Upon a naked wame, Oh

Let me in this ae nicht
this ae, ae, ae, nicht, oh
Let me in this ae nicht
An' I'll ne'er speir back again , oh

It means he has laid lots of women
and to "let him in" this one nicht and he'll never ask again

It's very old
It appears on Ord's Bothey ballads among other collections
Robert Burns has a version of it