Its not about Romelu Lukaku happy or not with Inter Milan but Chelsea can controlling what the future team for Lukaku, last rumor Chelsea want to sell Lukaku for Saudi Pro League team but Lukaku want to stay for playing with European teams. I think Inter Milan has offering higher bid than Saudi Pro League team if want to make Lukaku keep staying, for loan option seems impossible for Inter Milan and Chelsea want to get much money after selling many player to Saudi Pro League team.
Crucial situation what happen for Lukaku, one side he want stay and play with European teams between back to Chelsea or extend with Inter, but Chelsea want to sell him to Saudi Pro League teams.
al hilal is reported to have a very high interest in Lukaku but apart from al hilal, ac milan is also reported to have a fairly high interest in Lukaku, it looks like Lukaku's current position is very unfavorable. Chelsea's management now seems to really want to make big money from selling it, as long as it's still under contract, Chelsea has a big hand in selling Lukaku to whichever team drops the highest bid. let's see how far Lukaku struggles for his future in the European league (he really doesn't have a big interest in playing in the SPL).
And to be honest I didn't expect Romelu Lukaku to be in the position he is in now. Chelsea really only want to profit from selling Lukaku to the Arab league. But Lukaku has even openly not wanted him to play in the Arab League. Even Lukaku doesn't have a problem if his salary has to be cut in order to stay afloat in European football. and he still really wants to play at Inter Milan. I think what can save Lukaku's current situation is Inter Milan who have to buy from Chelsea. because if not, then Chelsea might actually release him to the Arab League, namely to Al-Hilal.