straightbreaker 

someone of the same sex, usually a celebrity figure, who would cause a straight person to turn gay

Kat Von D is totally a straightbreaker. If I was a lesbian, I'd totally hit that.

straightbreaker by wildflower3915 January 7, 2009

Straightbreaker 

An individual of the same sex that you will go gay for; an exception to your straight preference.

"Who's your straightbreaker?"
"Oh, mine's Shawn Mendes!"

Straightbreaker by T'sway December 22, 2019