They’ve barely made it across Ohio when Billy Crystal turns to Meg Ryan and informs her that relationships marked with the possibility of romance can never work since “the sex part always gets in the way.” But what about when you willingly let it get in the way? After sex and maybe even after love, can sexual relationships transition to friendships?

On the hottest day of the most humid summer, I convinced my friend Sydney to ride the subway with me to Coney Island for a free concert. Once we found our way to a tiny square of pavement packed with people, sun beating hard, plaid capris sticking to her butt, that of course was the moment Sydney saw her ex-girlfriend. Being surprisingly brave for such a small person, Sydney went over to say hi, only to have to suffer through one of those conversations in which her ex purposefully refused to introduce her to her companion. Sydney asked if they could hang out soon; she admitted she missed her. The ex, though, said “it wasn’t a good idea.” On the F train home, sunburned, sweaty and sad, Sydney was incredulous. “How can someone love you enough to spend time with you when you’re together but not enough to see you when you’re apart?”

Sydney and her girlfriend had had one of those epic blow-out breakups, but what if you part on good terms? Where is all that tenderness supposed to suddenly go? One couple I know carried on in courtly behavior for weeks—sleeping at each other’s houses, going on dinner dates, holding hands at the video store—there was just a distinct lack of sex.

But the idea that you and your former paramour could at any moment start rolling around on the floor in an amorous embrace is always in the back of your minds and can make for a dynamic—or torturous—friendship.

“If you play up the sexual tension, it can be fun,” said one friend who now thinks of her last boyfriend as a bastard, “because then you can just make fun of each other.” Unable to laugh it off, though, you may just find yourself giving hugs that last too long, harmonizing in the car to all your favorite songs (I’m not the only one who does that, right?), and going in for kisses on the cheek but somehow getting the lips instead. It seems that much of a successful friendship post-break-up is just a mutual agreement to pretend that’s what you are. And that pretending may be just what makes the status of your new relationship so hard.

When I asked a friend if he thought he was able to still be friends with the love of his life because of that very fact, he scoffed at me. “Before you’re dating and while you’re dating you feel comfortable enough to say anything.” It’s only once you break up and the subsequent need to censor yourself, he said, that strains the friendship: “There’s a lot of awkwardness created because you’re constantly holding things back from them.”

But it does seem cruel and somewhat inexplicable that friendship with a past love should be so hard, that two people can go from best friends to not friends with a break up. I want to think that it’s a matter of maturity (not enough) and pride (too much). If we could just act like grown-ups, we’d use Bombay Sapphire as a salve to the relationship sore. Getting a little sloppy over drinks to coax civility and kindness, we could reminisce about all the charms we loved so much in each other (reading aloud in bed, knowledge of every ‘60s girl group, great grilled cheese), and be drunk and benevolent enough to forget or overlook the annoying stuff; we could work it out.

But it’s a bit more than that, too. A sweetheart, more than anyone, sees us in all our fallible glory: crusty-eyed in the morning, cranky with hunger, sad on Sundays. The amazing thing is that they manage to still like us, love us, even. Once that love has been altered into some new form, perhaps we just feel too vulnerable to put on a face brave enough (and maybe a little mask-like) for friendship. Even after going through the wringer, people eventually put themselves back on the line for love because it’s irresistible. Friendship, too—while not necessarily containing a promise of getting laid—does offer perks as beauteous and supportive as romantic love. Doesn’t it seem like we should have the smarts and the will to forge a friendship with the one with whom we’ve shared time, stories and bodily fluids? The nature of the relationship may change, but it doesn’t just slip away like Mike McPherson. Once you love someone, you’ve got to live with that.