Lukaku scores first goal for manchester united and mourinho is happy for him

I think there may be some confusion here!

Romelu Lukaku has actually played for Manchester United since 2017, and has scored many goals for the club. In fact, he has been one of the team's top scorers during his time at Old Trafford.

However, José Mourinho, the former Manchester United manager, was not in charge of the team when Lukaku scored his first goal for the club. Mourinho was the manager of Manchester United from 2016 to 2018, but Lukaku joined the club in July 2017, after Mourinho had already been in charge for a year.

So, it's unlikely that Mourinho would have been "happy" for Lukaku on his first goal for Manchester United, as he wasn't the manager at the time!