Why am I disappointed at him being professional for once that he's not breaking the laws of God and men? This is good! Lame for now, but good. Growth, maturity if not progress.
Also there's no denying that the risk in taking any relationship to the next step is that it's very likely all the bridges will be burned once all is said and done. If it goes wrong, they'll lose their new friend, partner in crime, and fellow deviant on top of a lover. Leaving things as they stand, undefined, is safer.