Was it really necessary that I ____ there watching you the entire time you were rehearsing for the play? It was really boring watching you repeat the scenes over and over again.

Subjunctive form with adjectives: It + is/ was + neccessary + that + S + (should) + V.

Do I really need to sit there watching you the whole time you’re rehearsing for the play? It’s really boring watching you repeat the same scenes over and over again.

Answer: REMOVE