Coming Out

So I'm 18 and I've known I'm pan for YEARS but hadn't said anything to my parents because I've always ended up dating guys. Well I have a thing for a friend of mine who is genderqueer and my thing may turn into a dating thing and my only dilemma is how do I come out to my parents? They're not homophobic, but they're also people who just think that pan is a fancy term for bi. They're also not uber religious, which might make it a bit easier. Do I tell them if I start dating my friend or not tell them and just show up or just tell them before anything happens? I'm so confused