Lukaku will feel happy to continue his career in Inter Milan but he and Inter Milan will have to finalize another deal with Chelsea. Will Inter Milan buy Lukaku in this summer? It's very likely they won't do it as in the last season, Lukaku did not play too well for them. His performance is far lower than how he played for Inter Milan before he was sold to Chelsea.
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.