Mooching family member (please help)?

My boyfriends brother was in a motorcycle accident 2 years ago, he is doing fine can walk etc. And he's been living with us ever since. he has had two jobs since he moved in and they didn't even last a day. He doesn't do anything but lay around all day and eat. He doesn't even clean up after himself, he doesn't do his laundry or dishes. He is completely supported by us. We provided him with a car, we pay his insurance, phone bill, groceries. Give him money for gas, him to go out and drink etc. keep in mind he is two years older than us.

I have told my boyfriend, I wanted his brother to leave, he says "it's not that easy, and he's trying to get a job"

His brother is essentially the only family he has, but that doesn't make it okay for him to mooch off us. I've gotten to the point I don't know what to do, I don't want to stay here and clean after him, and I don't want to leave my boyfriend. What would you do??