Nice, oh, very nice! I loved how in character Snape and Remus were, especially the cutting dialogue and Snape's bitterness at the beginning. And Remus's phobia about being tied up was extremely vivid.
Very lovely turn towards understanding and mutual attraction too - both Remus losing control during sex, and Snape's way of lovemaking were very hot.
Thanks for writing and sharing this enjoyable forced-bonding variation :).