What happens when a woman who has only ever dated other women realizes that she is now also interested in men? In an article from xoJane [1], a woman shares her story about recently coming to identify as bisexual after years of identifying as a lesbian.

The woman in the adjacent movie theater seat wants to kiss me. I know because after our first date she texted to say so.

"You should have," I replied.

A year ago I would have meant it. In fact, this woman — rangy, big hands, artfully mussed hair — would have slain me. Two dates in, I'd be camped out in her apartment, stealing her jeans and walking her doddering lab.

"Guess I'll have to ask you out again," she texted.

"Guess I'll have to say yes," I wrote.

I stared at the words. "Have to." Implying something forced, inalterable. In truth, I only wanted to want her. After 15 years as a lesbian, suddenly, what I really wanted was a man.

Coming out as a lesbian was easy. At 19, I benefited from battles my foremothers fought; I was a women's studies major — that's the kind of stuff we actually say. My university had an LGBTQ center, my mom was a therapist who came to specialize in queer issues, and when I told my grandmother, she thought for a moment then said, "You know, I just don't care."

Institutional and family support, check. But what about role models? What did a lesbian even look like? Today's kids have Ellen Page and Portia de Rossi [2]; then, my only option was KD Lang. Now, I love butches. My problem was I didn't initially realize butch was a type of lesbian. I thought it was the only type. So, I tried to be butch. (That noise you hear is every butch in America laughing. It sounds like this: heh.)

Before long I was back dressing like a Slavic hooker and unless I was actively going down on another woman, everyone figured I was straight. Still, once lesbians got beyond my exterior, my orientation became apparent. I had never even slept with a man. But suddenly, I wanted to have sex with a man.

There's nothing lesbians hate more than women like me. I know, because back when I was a lesbian, I hated me. Or at least I empathized with my ex-girlfriend when she talked about hating who I've become. Bisexuals, she said, glommed onto lesbians because they feared their fathers, or had been devastated by ex-boyfriends. For them, lesbianism was a vacation from the pressures of heterosexuality. Even feminine lesbians were to be regarded with healthy skepticism. You never knew when one might turn.

To me, this sounded a bit alarmist. I'd spent my adult life in three consecutive long-term lesbian relationships. So what if I crushed on James Dean and shopped at Bebe? I wasn't on some heterosexuality sabbatical. I was gayer than my girlfriend, if you really thought about it. She might change her own oil and panic when asked to hold my purse, but her route to lesbianism was littered with heterosexual missteps. Sad hand job notwithstanding, I was "gold star" all the way.

Until a week after I dumped her, when I found myself having sex with a man.

"Found myself," implying both a lack of control over my own life and the end-product of self-evolution. Obviously, my choices led to our first date and this, our second. I was the one who created an OkCupid account, labeled myself bisexual and bantered my way to this moment — ceiling fan above, him reaching for a condom, me thinking sure, why not? Still, those choices felt instinctive, not chosen. Certainly I hadn't considered their impact on my identity. Nor were they the apex of years of soul-searching. In that porous post-breakup period, sleeping with a man simply felt right.

Sex itself may have seemed self-explanatory, but soon heterosexuality's societal components destabilized me. For years I'd absorbed straight culture, but from a safe distance. Smug in my otherness, I'd read about heterosexual rites and rituals in women's magazines, watched straights cavorting on reality TV. Now I felt like an anthropologist with no primary sources, suddenly thrown into the field.

Why hadn't anyone told me men stay hard after they come? Speaking of hard, was I supposed to play hard to get? I felt myself morphing from sexually confident lesbian to insecure straight girl. Heterosexuality had brought me to my knees, figuratively and literally.

The literal part was much more enjoyable, except for my intense blow job anxiety. Back while all of you were practicing on bananas, I was sleeping with a picture of Candice Bergen under my pillow. I couldn't ask the guy I was dating. Mainly because I already had. Twice. His response? "The equipment's pretty simple." If I asked him again he'd think I was needy.

Turns out if you're a woman and have needs, you're needy. I didn't know. When you're a woman who dates other women, it's all just a writhing mass of mutual need. Which is exhausting but at least it's honest, which according to Cosmo you're never allowed to be. Cosmo also told me I texted too much and I wasn't supposed to ask for exclusivity for another three months, and oh, look there's a quiz to help me figure out what dating type I am.

Straight women have so many rules to follow:

How to catch a man.
Gift-giving tips.
Recipes for romance.
Is he marriage material? Are you? What exactly is marriage material? Probably chiffon.
1001 sex tips.
I'm sorry, did you just tell him you love him after labor day?
Whatever you do don't order chai. Men hate chai.
1001 flirting fails.
Clothing men hate but women love.
Your tank top repulses him.
Are those culottes? Who do you think you are? Lena Dunham? Men hate Lena Dunham.
Your bra straps are showing, you whore.

At least when you're dating a woman you can act as crazy as you feel. Maybe that's part of why I tried to go back. Not because lesbians are more accepting, but because with women I know what's expected. More importantly, I know what to expect. Or maybe I accepted that second date because I hated fulfilling the same stereotypes I'd spent my whole lesbionic career fighting. My sudden drive to date men might feel natural, but I know what everyone thinks. That they should have trusted their instincts, I was too femme all along. Or, if they were a more prejudiced type, that I just needed to meet the right man all along.

What about the woman with the artfully mussed hair? The one I've selfishly sucked into my turmoil. The one who just wants an easy evening out, the possibilities a second date promises, sealed with a kiss. In my periphery, I see her hand on the armrest, palm up, a clear invitation to lace my fingers through. She's perfect on paper, yet holding hands seems pointless, as erotic as stuffing an envelope or blowing my nose. I feel like my mother or Kelly Ripa [3], a straighter than straight woman, not myself at all. I have no business on this date. I'm a phony and a defector, an accidental fraud.

That's what I'm thinking when I excuse myself early. Yet alone in my apartment, I don't feel like a phony. At 19, I walked blithely down the street holding hands with my girlfriend. So what if men hissed "dykes" at us from their cars? Now 35, I'm still not defined by how others might perceive me. My only responsibility is to harness my younger self's courage and be as true to who I am now as who I was then.

— Sarah Terez Rosenblum

Check out more great stories from xoJane:

• How to Have Casual Sex Everyone Feels Good About [4]
• Reasons Why Reading Is Obviously Supersexy [5]
• How Moms Talk About Their Bodies Matters [6]