Is there such a thing as being fully, exclusively straight?

Silly question I know..

But obviously, thinking someone of the same gender is attractive doesn’t count

I mean like never had any sexual or romantic interest in the same gender, never fantasized about it, never wanted to date or hook up with the same gender, no random intrusive thoughts, just basically zero curiosity whatsoever.

And I feel like we as people can get a little curious. If not everyone, almost everyone has to have thought of something a little homo AT LEAST once.. even the ones that claim they’re “homophobic”. Because I know I have, and I’m definitely bisexual.