Six months is a tricky time... about enough to repair most of Harry's mental fears, and enough to allow him to stand on his own. On the other hand, it's such a 'comfortable' arrangement - Lucius gets his kinks fulfilled, Ron has his best friend with him without having to fret that he might be miserable someplace else, and Harry will not be alone and has a sort of family to cling to.

Still, the Harry/Lucius angle is very dysfunctional, so I think once Harry is himself again, he will leave. Or begin to lead his own life if he stays. But more likely leave.