Working at two different brokerages as an agent?

[Joseph Testa]

I have a bit of a trick question and want to see if anyone on here might have the answer. I am a 21 year old real estate agent out of Boston, MA.

I began work a brokerage about six months back, but have recently been searching for work as an assistant under a more experienced agent in order to learn the ins and outs of the business. 

I know you can't work for two brokers at once, but is it acceptable for me to be an assistant to an agent at another brokerage other than my own?