This image was originally scanned by me, and posted at http://moe.imouto.org/post/show/8186 , from where Slaash got it. (the other Ren post I made there was also scanned by me, in case someone posted it here and I can't see it due to nudity)
Slaash posted it before I even re-registered here (Oct 2). As far as I know, danbooru wasn't accepting registrations back then (scanned in September), and registration was broke when I noticed and tried on Oct 1. Didn't notice the guy posted my scan, or think about uploading my scans til now.