Agreeing with Quath on this one. I think everyday run of the mill roommate issues will come up, and that's about it. I think it will be clear enough that you both care about his needs and are there to share with him rather than you are there to take her away... why would you move in WITH HIM if you are only interested in taking her away or her only being interested in leaving.
Thanks for saying you aren't looking for a label though. It isn't necessary to have one or identify as one... it really just helps others put you in a box and understand more. for that I'm glad you found a place to ask questions.
That being said, if they love each other beyond sex but more than friendship then perhaps their relationship is asexual? Would that fit somewhat?
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