Vancouver Morris Men apparently don't say where they got that, but a very similar verse occurs on English Country Music (Topic TSCD607, 2000: a revised edition of material originally issued in 1965 and 1976), in the middle of track 24, a medley of schottisches. Walter Bulwer sang it.

Old Mrs Huddledee
Came to bed to cuddle me
Cocked her leg right over me
To keep her belly warm-o.

The recording was made in 1962 by Bill Leader.