Should I give a kid zero even if he’s being "nice"?

I give a lot of extra credit for kids who do real work and have good behavior. I'm very generous we them. I always tell them they can have extra credit as long as it's good work and they're good in class. I have a bunch of very good kids that have good grades. I have a bunch of bad kids this year too. One of my good kids and I've had him a couple years, good looking kid, good student, very good kid, very hard working. He asked if he can do extra credit. I say sure. He does it and it's not really what I'm looking for. Not good, but I feel like I should still give it to him since he's an awesome kid. I'm not sure what to do though. I feel like giving him a 0 on the extra credit will just upset him. And I don't want to ruin my relationship with him. And I don't want him to feel bad. Honestly he doesn't even need it. He has a 95%. But he's still asking for it so I feel obligated. I don't want to throw it out but it's like 15 points and I feel it's just wrong to give it to him when it's not what I'm looking for. I'm just not sure what to do. What would you do?.