The New York fad has really taken off, according to a sex tutor who says he has around 200 clients that he watches while they’re making love.

Therapist Eric Amaranth has also observed semi-famous couples ‘doing-it’ in front of him, sometimes offering them sex toys and tips during and after the deed.

Aniela McGuinness explained to the Sun newspaper that it has improved her confidence in the bedroom. “I was nervous at first, of course. I wasn’t sure how easily I would be able to relax.

“But it was an incredible experience. I had orgasms like I’ve never had before – with him in the room.”

McGuinness has coached couples on the verge of breaking up as well as single people who are interested in pleasing themselves.

‘Students’ can choose between virtual sessions via Skype, for £110 an hour, or coaching in the flesh – where he’ll come to a designated hotel room and watch for £150.

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