“Bread and butter”
When I was out shopping, two of my friends strolled arm-in-arm. Upon meeting a garbage can they unlinked and one shouted ‘bread and butter’. I asked met up with her recently to ask her about the saying and ritual. She said, “When you are walking with somebody, and there’s like a stationary object and the person you are walking with goes on one side of an object and you walk on the other you say ‘bread and butter’.” When I asked her why she does it and to explain it further she replied, “My mom does it. Say you are holding hands and a pole comes in between you and you have to let go of hands you say ‘bread and butter’. It’s like to um make sure you stay together and nothing gets in between you two.”
The folk practice is only used if you must let go of your partner. You then say the phrase and reconnect. It is an idiom to mean one’s livelihood or means of living, and I suppose you are referencing that as a means to getting by the obstacle. It is a phrase used only when one does not want to be separated from the other and wishes to reconnect on the other side of the obstruction in the path. It also may refer to the relationship of bread and butter that they so naturally go together, just like you and your partner.