You've got to be wary of encouraging this other person to have feelings for you that will not be reciprocated. Eventually, your S.O. will want sex, don't you think? It's hard to have sexual intimacy with someone you feel unattracted to.

But it sounds like you've tried to be fairly honest with this other person. Still, I'll bet the two of you have different long-term expectations. That's apt to lead to somebody getting hurt.