How to deal with junior associate repeatedly asking for extensions?

He is fine as a person, and each time he is always very polite and apologetic, so proper that I find it hard to reject these requests. But it's getting a bit out of hand. He asks for extensions every third assignment, and sometimes on the same assignment he would ask for a second or third extension.

I wonder if this is a bad habit left over from school, but I do want to deal with this as carefully as possible because he does do good work and I think he's pretty well liked.

Author: CrimsonClover__