Turnabout is Fair Play (http://telete.livejournal.com/24665.html) by bertee is pretty hot IMO. It's also at AO3 (http://archiveofourown.org/works/303780). This one totally fits your request, but it's slightly dubcon on Dean's part, so I'm just warning in case you don't like that kind of thing. Dean does have a good time though!

I'm also going to give you a link to One Foot in the Gate of Hell (http://oxoniensis.livejournal.com/381777.html) by oxoniensis. This one isn't toppy Sam, but it's very hot. I haven't found all that many Sam/Ruby/Dean fics out there, so I didn't want you to miss out even if it doesn't include toppy Sam :)

One Foot in the Gate of Hell at AO3 (http://archiveofourown.org/works/21336)

Edited because I can't seem to spell gate today. Ugh.

Edited 2013-08-06 06:30 pm (UTC)