Make a game of it...
Say ' hands up whos not gay' .. awkward silence.. presto
Marry a lesbian in the same situation and have lovers on the side.
"You know I'm gay, right?"
Hi dad... I'm gay.
BTW, they probably know already. Parents aren't blind and stupid.
Say it in rhymes:
Heard the news?
I´m into dudes!
You know how a lot of parents worry about their son getting a girl pregnant..... guess what?
You may or may not know this but I ( then say what you got to say)
"I'm gay. Lol, burn on me! But seriously, I enjoy women sexually."