As gender and relational boundaries become more fluid, millennials are crafting their own approaches to coupling.

As gender and relational boundaries become more fluid, millennials (and their more adventurous elders) are crafting their own approaches to coupling. A far cry from the “free love” proponents of the ‘60s, today’s “monogamish” couples tend to be young professionals in committed relationships seeking occasional outside companionship.

There’s even an emerging niche in the post-Tinder world of dating apps designed to accommodate these behaviors. A recent Washington Post article on the subject highlighted OpenMinded, “a new kind of dating site for a newly mainstream lifestyle: one in which couples form very real attachments, just not exclusively with each other.” While there’s no shortage of hookup and even affair-facilitating apps, OpenMinded targets a more progressive group that sees sex beyond monogamy as part of an open dialogue between partners, rather than as an illicit taboo.

While the idea is far from universal, it’s gaining steam. A film on the topic—Monogamish—was recently funded on Kickstarter and is due out later this year. The film examines beliefs about dating and marriage that our culture often takes for granted.

“The idea that there is a one-size-fits-all format for relationships misses the complexity of human relationships,” said psychology professor Art Markman in Yahoo Health. While most brands continue to create messaging with traditional couples in mind, the growth of apps such as OpenMinded show that their real customers are much more complex.