The only way this can stop is if the person that is replying to you decides to delete the original message... OR if they have it in their settings to NOT send original message in replies.

I always delete other email addresses before I forward something. I can't stand for that information to be forwarded over and over.

There is a setting in your email options that you need to look at. Look under tools-options-click the message tab-click advanced settings-be sure the box that says "include message source on reply" is not checked. Then click ok-then ok again. If it is checked, then the message will be included upon a reply.
Some users like to keep it checked, then if you are having a conversation with someone you can refer back to a section you might have forgotten what ...

There is a setting in your email options that you need to look at. Look under tools-options-click the message tab-click advanced settings-be sure the box that says "include message source on reply" is not checked. Then click ok-then ok again. If it is checked, then the message will be included upon a reply.
Some users like to keep it checked, then if you are having a conversation with someone you can refer back to a section you might have forgotten what was said. The settings on your email program, might not be exactly as I described but if you look around you will find it. Good Luck.