Poor romantic comedies. Even our criticisms of them have grown stale.

“They’re not as good as they used to be,” we moan, yearning for some purer time when we didn’t know the time-tested beats, the inevitable outcomes and the dynamics seemed more attuned to How We Date Now. Even the character types have started to become one big blur of clichés.

How refreshing, then, that “Sleeping With Other People” gives the form a solid adrenaline boost by managing to both operate within the comforting constraints of “When Harry Met Sally’s …” can men and women be friends premise, and still be its own unique, modern creation.

Writer-director Leslye Headland, as a follow-up to the bawdy girls’ night out film “Bachelorette,” accomplishes this by getting the sex out of the way first, and then making it off-limits.

Headland knows that the litmus test is not the theoretical happy ending, but the characters — and Jake (Jason Sudeikis) and Lainey (Alison Brie) prove to be some fascinating specimens. We meet them in college, where they lose their virginity to each other in a harried one-night stand on a New York rooftop, then again a decade or so later in a meeting for sex addicts.

Neither are actually sex addicts, at least in the clinical sense. But Lainey can’t seem to stop cheating on her boyfriends with one old flame (Adam Scott), and Jake cheats as a way out of relationships he’s too scared to end with a normal breakup.

So Lainey and Jake decide, despite their mutual attraction and history, to be just friends. It is, quite simply, the story of two people who are prone to self-sabotage, falling in love and trying their hardest not to act on it.

But this is no exercise in prudish innocence. Sex is there. It’s everywhere actually, and not just in innuendo.

Some might be troubled by the fact that their exploits during this emotional relationship phase are not, you might say, equal. Jake gets to date and sleep with many other people. Lainey doesn’t.

We’re told this is her choice. That she can only recover by abstaining.

But ultimately, their dynamic works, despite the faint alarm of outmoded gender expectations. Sudeikis and Brie have an easy, heady chemistry — although it does take a bit of imagination to accept them (seven years apart in real life) as college contemporaries.

In the end, this isn’t exactly a portrait of modern dating. This is a fantasy world, where even a kindergarten teacher has a spacious New York apartment and scores of expensive outfits.

The rom-com is not dead, in Headland’s hands at least.