One can get around the automatic NSFW detection by chaining it to another URL shortener, for example: <a href="http://nt.gd/lx2hr0" rel="nofollow">http://nt.gd/lx2hr0</a>. Might be useful to either detect this, or warn that the next link also hosts a redirect.
Spotted a little typo:<p>>When you share a short URL the <i>[recipient]</i> will be saved some potential embarassment if they're not in a location suitable for viewing NSFW content.