Even if he was going back to the chelsea and it will not be included in the starting line up and so there's no choice for him other than try to stay at intermilan. Intermilan's owned was also trying to sell its club. That means the future for this club is still remain unknown.
Lukaku has been taking a good decision by staying at inter rather than going back to the chelsea again but i don't even think inter will make him permanent caused by club was facing financial problem.
The owner of inter will be facing the dead line to pay the loan. that's also a very big loan.