Teenagers lie – that’s nothing new. But are the activities they’re concealing from anxious parents in this oversharing digital age more extreme, more likely to define their lives and those of the people around them? James Fritz’s 90-minute debut, the first of two Hampstead Downstairs transfers to Trafalgar Studios, dives headfirst into that murky paranoia, with dramatically mixed but thought-provoking results.

“We’re completely pro sex.” Rashdash, who collaborated with Alice Birch on this anarchic challenge to pornography, are not objecting on prudish grounds – their concern is the corrosive impact of degrading, dehumanising material. We are all affected, and we all need to seek a solution.

A sci-fi special would be incomplete without the profoundly influential figure of JG Ballard, a writer who, when he began his career in the late Fifties, fully subscribed to the notion that  “sci-fi is the literature of the 20^th century.” Unlike the “Hampstead novel,” he once said, “the sci-fi novel plays back the century to itself.”

There is nothing erotic or titillating about The Institute of Sexology, an exhibition the Wellcome Collection plans to keep open for a year. Those expecting a display of fertility symbols, fetish objects, kinky clothing or sex aids down the ages will be deeply disappointed. Just about enough objects and images are included to keep you interested, but the bulk of the show is not dedicated to sexual practices but to the 19th- and 20th-century doctors, anthropologists and psychologists who spent their lives studying sexual behaviour. 

At the risk of endorsing national stereotypes, I’ll still describe Yann Gonzalez’ feature debut You and the Night as a very French film. Its appearance in Critics’ Week at Cannes last year brought comparisons with Francois Ozon and Pedro Almodovar for a combination of style and sex, arguably at the expense of substance. And you can’t help feeling that the ghosts – it’s a work very much concerned with ghosts and fantasies – of Cocteau and Genet are lurking somewhere too.

Chris Carter and Cosey Fanni Tutti are a living lesson in the rejuvenating power of remaining experimental in art. Their music holds its own alongside the young guns of electronica, who indeed frequently idolise them, and in person they frequently seem as excited about possibilities and open to new ideas as artists just starting out.

Playing against his wholesome appeal, Joseph Gordon-Levitt's debut outing as a writer/director spins a comedy of internet porn addiction, love, family, church – and a man who loves to do his own cleaning. Set in contemporary New Jersey, Gordon-Levitt is Jon, a muscle-bound young greaser who loves the ladies but prefers his own hand.

I am increasingly finding it almost impossible to express just how bored I am by Miley Cyrus. I mean, seriously, are we really in such a fix that this guff is a serious talking point? A second-generation celebrity and former child star seems to be going off the rails a bit? OH REALLY, GOSH, THIS HAS NEVER HAPPENED BEFORE, PLEASE TELL ME MORE. A young female celebrity is flashing her parts? SWEET BABY JESUS ON A BORIS BIKE THIS IS AMAZING. A white pop star is crassly adopting the tropes of black culture? WOW NO WAY, YOU'RE LITERALLY SHITTING ME.

Shot in Seventies throwback grainy-cam, Amanda Seyfried is superb as Linda Lovelace in the surprisingly entertaining biopic Lovelace. Peter Sarsgaard, Sharon Stone, Robert Patrick, Bobby Cannavle, Hank Azaria, Chris Noth, Juno Temple and James Franco round out a dream cast.

Having begun as a piece of fan fiction derived from the Twilight movie series, EL James's Fifty Shades of Grey has blown up into the publishing phenomenon du jour. It's supposedly the UK's fastest-selling book of all time, and has sold nearly 50 million copies worldwide. In the process, with its copious descriptions of BDSM (or bondage, discipline and sado-masochism), it has gathered a vast mostly-female fanbase and fostered the creation of the term "mummy porn".