You -should- be ok as the feed source, and you probably won't be penalized for it, but there's the odd chance that his site gets the rank for your content. In this case his domain is older than yours, and there's a chance that could have an effect. His site is also PR 3 but yours is PR 0? His may get the credit in the off chance that their algorithms aren't clever enough to know better.
They will mainly be trying to determine if you (or he) is just scraping content and has no additional value. Too many pages added at once might look like you're spamming too, and RSS 2 Blog type users should consider that.
You might try this duplicate content check, and try to keep it low 30 to 40% where possible.
http://www.webconfs.com/similar-page-checker.php
http://www.teenist.com/
is 65% percentage similar to
http://www.justapornblog.com/
http://www.teenist.com/next-door-nik...pringer-video/
is 39% percentage similar to
http://www.justapornblog.com/2006/07...pringer-video/
You could always block him in .htaccess
I like this method, untested..
Code:
SetEnvIfNoCase Referer "^http://www.teenist.com/" norss
<Limit GET>
Order Deny,Allow
Deny from env=norss
Allow from All
</Limit>