QUOTE(closeup @ Nov 25 2014, 09:55 PM)
From the Urban Dictionary:
ruin
To have sex with another in such a manner so the partner is never quite the same.
Really? Urban dictionary? Still, the definition holds an ambiguous outcome, could be positive or negative.
Webster (the real dictionary) says:
To damage (something) so badly that it is no longer useful, valuable, enjoyable, etc. : to spoil or destroy (something)