As above, I was surprised not to find this one.
I assume that "play barley-break" refers to lying down together in the corn fields, a common theme in this thread so far!

NOW IS THE MONTH OF MAYING

Now is the month of Maying,
When merry lads are playing,
Fa la la la la la la la la,
Fa la la la la la la.
Each with his bonny lass,
A-dancing on the grass.
Fa la la la la,
Fa la la la la la la la la la la la.

The Spring, clad all in gladness,
Doth laugh at Winter's sadness,
Fa la la la la la la la la,
Fa la la la la la la.
And to the bagpipe's sound
The nymphs tread out their ground.
Fa la la la la,
Fa la la la la la la la la la la la.

Fye then, why sit we musing,
Sweet youth's delights refusing ?
Fa la la la la la la la la,
Fa la la la la la la.
Say, dainty nymphs, and speak,
Shall we play barley-break ?
Fa la la la la,
Fa la la la la la la la la la la la.


Notes: found in "The National Song Book", authorless, but music by 'Thomas Morley 1595'.
My copy of this book has no cover, but was in use in Cardiff schools in the late 1950s

NP