What you are hearing is the word 'ese' where the e on the end has an accent mark. It's a slang term for your homie or friend. Like calling a friend 'Holmes', it is a compliment alluding to the size of your friend's penis, therefore giving him a compliment, even if it's not true. Typically you wouldn't call someone ese unless you knew them very well. It could get you beat up if you called someone that and they might take your bike.