It has 4 tubes/inflations setup to milk either 2 goats or one cow. How does two goats at one time work? I have to turn off suction to and make it release to easily get the teat out when the milk flow slows. If it is still going on the second goat when the first is done, would you just stop machine milking and finish out the one that isn't done with hand milking? I don't want to damage teats by pulling them out with suction still going strong...if that is what would inevitably happen if I don't stop suction and release the vacuum?