Well, like I tell anyone it's relevant to, it's not who you do, it's why.
For example, a gay-for-pay male porn star, sure, he can have sex with other guys, does it necessarily make him gay? No, because he's not sexually attracted to his co-stars.
A virgin can be very aware of who they are attracted to, even without doing the deed.
A lesbian woman who gets raped by a man, does that make her bi? Nope, she's not attracted to men.
Some university student is bi-curious, so they mess around with the sex for a bit, realizes they're just not feeling it, just because they had sex with men, and women, does that make them bisexual? Nope because of a lack of attraction.
This is the why in my first sentence up there.
I believe you're wrong on your first line there, sexual orientation is about who you're sexually/romantically attracted to, at least that's how the general populace sees it, and that's how it's used in our vernacular. Although, there are people who can be sexually hetero, and romantically bi/pan, or any combo thereof.
But my sexual orientation without bringing in the mushy good stuff? Still pansexual.
Captcha: "would affigire" But I just met her!