Didn't you know? It's 20-bi-teen! What better time to get schooled on the ins and outs of bisexuality. In this ep, a couple from season 2 return to talk about the difference between being bi and pansexual, and what it's like when everyone around them assumes they're straight. Plus queer author and columnist Emily Writes comes out in her 30s and we ask some bi and pan teens if biphobia is something they're familiar with.

There are at least as many bi and pansexual people in the world as lesbians and gay men combined, at least according to surveys of western countries. But bisexuality is poorly understood - leaving bi and pansexual people feeling that their sexuality is invisible or invalid.

In Episode 1 of the new season of BANG!, people who are "attracted to more than one gender" share their experiences, and Dr Nikki Hayfield highlights some particularly damaging, often "biphobic", stereotypes.

To the outside world, Rose and Sam* look like any other straight couple. They're in their mid 20s, affectionate and obviously really into each other. The thing is, they're not straight.

Sam identifies as pansexual and Rose is bisexual. People define each of these sexualities in different ways, but for Sam pansexuality means that he's attracted to people irrespective of gender (as in, it's not important) and for Rose bisexuality means she's attracted to people "across the spectrum of genders."

For those shouting "but bi means two!", some people still use bisexuality to mean they're into just men and women, but others have broadened the definition as a response to the increase in trans identities and in resisting binary understandings of gender.

Both Sam and Rose came out in their early 20s, both had same-sex experiences and attractions in their teens and, initially, both put them down to teenaged "confusion" or "acting out".

As Sam puts it, "Heterosexuality was expected of me and that's why it took quite a while to realise I wasn't that. It's why my parents still don't know ... I wouldn't be disowned or anything, but it would confirm that I'm the sort of black sheep, and that I'm less of a man in some way, and that doesn't feel good."

Rose grew up with an openly lesbian aunt, her family environment was welcoming of queerness. But she thought bisexuality meant 50% attracted to men and 50% attracted to women, and that the label didn't fit her because she's attracted to men more of the time.

That's until she turned 21 and stumbled across a Tumblr post. …

Go to this episode on rnz.co.nz for more details