One afternoon in seventh grade, my friends explained the bases to me. There was kissing, then there was feeling-up, then there was manual and oral sex, then there was "sex" — i.e., penis-in-vagina intercourse. The discussion did not include how couples without a penis and a vagina had sex, nor did it include the fact that only a quarter of women reliably orgasm through sex of the "home run" variety. I learned not only that PIV intercourse was more important than any other activity but also that once I had it, I'd be forever changed, because I'd no longer be a "virgin." As it turns out, though, this is only one of many ways to define "sex."
"I think many people equate intimacy with the in-and-out of sex," Amy Levine, sex coach and founder of Ignite Your Pleasure, tells Bustle. "It's often due to lack of relationship role models to teach them about true intimacy and lack of sex ed. Instead, many people learn through trial and error and may not have a better understanding of what it takes to have better sex until the info pops up on the web or social media to educate them."
You can define sex however you want, but to give you an idea of what the possibilities are, here's how some people define sex for themselves.