By the end of their dinner at a small Italian restaurant in New York’s West Village, Leah is getting antsy to part ways with her boyfriend Ryan, so that she can go meet up with her boyfriend Jim.

But Leah and Ryan, 32 and 38, respectively, don’t fit these preconceived ideas. She wears pretty skirts; he wears jeans and trendy glasses.

They have a large, downtown apartment with a sweeping view and are possessed of the type of hip hyperawareness that lets them head off any assumptions as to what their arrangement might entail.

“I like everyone to meet each other and be friends and stuff,” he explains.

"There was a side of me that was ecstatic – the teenage boy in me that wants to fuck everything I see," reveals Ryan, a millennial in an open relationship.

And in this, Millennials realize that they’re pushing the boundaries of the sexual revolution beyond what their parents might have expected and their grandparents could even conceive.

By and large, Leah and Ryan feel comfortable with friends their age knowing that they sleep with other people, but are not as comfortable telling older people (for this reason, and for fear of professional repercussions, they’ve asked me to change their names for this article).

“I remember the first night, I was telling him about my difficulty with monogamy,” she says.

“I don’t know why I felt the need, but it must have been on my mind a lot.” In almost every relationship she’d had, she’d found herself cheating, though she didn’t know if this was a character flaw or a problem with the conventional system. “I was just trying to get into your panties,” he says to her, laughing.

"But the other side of me was concerned about what this means in terms of intimacy and how the dynamics would work." When Leah and Ryan met at a wedding four years ago, they didn’t expect to develop this type of arrangement.