IMO, he cannot stay any longer, the glass is broken, it's disheartening, but showed him that we don't longer trust him.
We are considering him a promise that never delivered. Accepting the 70mil offer from Tottenham, we have proved that are anxious to cut our loses and don't at all care about his future.
At this point the best scenario is to sell him for cash and hopefully this will end our financial troubles.
70mil cash is so much better than 10mil salary for Lukaku and no cash!