How do I tell my dad that I might actually not be a lesbian cause I ended up dating a guy..?

Been on here for a while and now I just need advice. For years I have only dated girls and never felt any attraction to men and if I did I discarded it as a friendship feeling and that’s that. But wtf I’m dating a guy and I do like him, but like I said I thought I was a lesbian. And polyamorous and genderfluid...
Complicated situation, I know I’m not bisexual because I’m not attracted to the gender I’m attracted to the person- if that makes any sense.
Besties help me out
How do I tell my dad abt my changing of sexuality?
What would you describe my sexuality to be?

What do I do