stop someone from using my email address

[aristosv]

Someone is using as a "reply-to" address my gmail account. And when people reply to him, I receive the replies. I know, its a weird thing to do, but he does it.

Now, I don't mind the pictures call-girls sent him, but I'm tired of all the emails I receive by game sites he registers on. And also all his facebook notifications.

Is there a way I can stop him from doing this?

Thanks