"ROUND ROOM, ROTUNDO

Mr Harry Clifton will, in addition to many old favourites, sing several of the following:

'The Adventures of Robinson Crusoe'
'Uncle John's Birthday'
'Don't Be After Ten'
'Never Look Behind'
'Ten Minutes Too Late'
'Happy As The Days Are Long'
'Welcome As The Flowers of May'
'The Leicestershire Squire'

And will, in conjunction with Miss Annie Kinnaird, appear in two original comic character duets."

Freeman's Journal, Dublin, Oct 25 1870

That's the earliest mention of 'Never Look Behind' I've found.