The scene:
The sexual tension that's smouldered through the film finally explodes as Keira Knightley and James McAvoy sneak into the library of the country manor for a knee-trembling quickie. She confesses her love as he hitches up her green ballgown and pins her wrists against the creaking bookshelves.

The turn-on:
This is your basic "danger shag" with a swanky twist. The fact that it takes place in the elegant interior of an English stately home as opposed to, say, a dingy car park behind Coles, takes it into fantasy territory by adding a sense of decadent glamour.

"Having sex publicly where no-one knows what you're doing, or somewhere that you might get caught can add an erotic edge," says Hellyer. "It's like that whole teenage thing of doing it without the parents catching you."

Knightley and McAvoy are almost silent as they get their rocks off in a scene propelled by their urgent passion. Hellyer does, however, have words of warning when it comes to hanky-panky outside the bedroom: "Don't do it in full public," she says. "And don't get arrested."

Your sequel:
"A quickie is all about the eroticism and intimacy of the moment," says Hellyer. "The better the atmosphere, the quicker she'll get into it." The lead-up to the sex is therefore particularly crucial and you'll need to work on having a good rapport with your partner so you're both receptive to sexual opportunities when they crop up.

"Any couple in an ongoing relationship can get a bit complacent, but it's easy to build in this sort of general frisson," says Hellyer. "Play footsy under the table over dinner, order her to take off her knickers in the restaurant bathroom, then go at it in the alley as you're walking back to the car."

Quickies, by their very nature, are fast and furious, diminishing the sexual returns for your partner. "It's not likely that she'll have an orgasm that quickly," concedes Hellyer. "But it is important that she's sufficiently lubricated." Her advice? Use your tongue to get things started then stand up and go for it. "Or if you're in the bedroom keep a bit of lube handy."

If your girl still isn't a fan of the quickie, Hellyer says this: "I'd encourage men in these situations to really make it about the woman and the fact that you're unable to resist her because she's so utterly gorgeous. If it's more like, 'Oi, I need a root', she's far more likely to tell you where to get off."