Brewer's: Go along with You
In French, Tirez de long, said to dogs, meaning scamper off, run away. Au long et au large, i.e. entirely, go off the whole length and breadth of the way from me to infinite space.
“To go along with some one,” with the lower classes, means to take a walk with someone of the opposite sex, with a view of matrimony if both parties think fit.