Wow! Thanks for your responses, ladies. Regarding those who noted that I would be contributing to HIS mortgage -- that's a great point.
I guess I'll just come clean all the way: he doesn't need me to pay rent, and in fact offered for me to just live with him without financial contributions. THIS IS VERY TEMPTING!!! (bad, bad, bad -- don't want to set the feminist movement back 50 years) Somehow, I felt like there is something slightly amiss about that scenario -- but I see that many of you ladies condone it? If I were to move in, should I just not bother with paying him rent?
I don't feel qualified to give you advice on whether or not you should move in with him, but I did want to suggest this - I also don't think it is right that you would be contributing to the morgage payment on a condo that you do not own, but understand not wanting to free-load. So, what about paying half of the utilities? That way you wouldn't be getting free housing, but you also wouldn't be paying for his condo. Just a thought...