Multiplayer co-op and savegames?

Does anyone know what happens if you
(1) save a game in multiplayer co-op with all players present and assembled at the same spot, then
(2) load the game in single player mode, do some stuff without the others, return to the spot where you left them, save again (e.g. in a new slot), and then
(3) load this savegame in multiplayer co-op again, next time the others are present?

Will they still re-enter the new savegame at the same spot and with the last state of their xp and equipment as in the old savegame? Or will doing stuff on your own in SP mode and saving the game without the others present mess up things for them?