The appropriate pronoun for this sentence is "he".
Hello,
This is (your name), (older brothers name)’s sibling. My brother has recently been accepted into a great university and my parents are throwing a surprise party to celebrate. You are invited to join us celebrating during (date of party). Make sure not to mention this to them as it is a surprise party.
Sincerely,
(Your name)
In what act 2 and scene 2???
The preposition is 'I' I think. I could be wrong.
