Buyer Representation Agreement

[Hal Waters]

I am newly getting into selling real estate and was curious about how a buyer representation agreement truly works... Lets assume I have been working with a buyer and have an active buyer representation contract with them.  How would I know my buyer signed a purchase agreement with another agent while under the contract agreement for me to represent them? Is this more of a good faith contract unless I were to find out they went under contract on a property?

How does that work?