Barry is an old college roommate of Louis Huang in New Jersey. Louis noted that they played a lot of basketball then. He appeared in the episode We Done Son. They invented a vitamin they call "Vitamin L" and tried to get it on the market but failed. Jessica described him to be an idiot who only wants money from them.
While Louis kept defending to Jessica that Barry just wants to hang out, it later turns out as soon as Barry asks Louis to invest money in Barry's online selling service, Louis realizes that Barry only arrived to ask him for money. This is also when Barry became more rude to Louis.
Louis later on did throw out Barry out of his house out of retaliation for Barry being inconsiderate and greedy.