~ Sitz'st du gut, so sitze feste ~
This verse means that a guest who knows when he's had enough is very welcome. See translation Sitz du gut so sitze feste for more info. The stein is probably by Marzi & Remy and marked "112 5", ca. 1900.
Sitz'st du gut, so sitze feste,
jeder Wirth liebt solche gäste.
If you are seated well, then stay firm,
every innkeeper loves such guests.
Translation: Roy De Selms
Photo credit: Unknown