Spencer Pratt and Heidi Montag are planning to have sex on the 'Celebrity Big Brother' diary room chair.

The couple - who finished in second place on the Channel 5 reality show earlier this year - have bought the throne for £3,000 and had it shipped home to the US, where they plan to use it as a Love Seat.

The pair - known as Speidi - often cuddled up on the chair as they talked to producers of the show, but resisted the temptation to indulge their passion for each other on camera.

A source told the Daily Star newspaper: "Speidi were very frustrated in the house and had to hold back several times. They can't wait to let themselves go when they get the chair in their bedroom.

"Spencer has already worked out some rather interesting positions he can try out with Heidi."

The pair are even rumoured to be thinking of filming their steamy sessions on the fur-covered throne for a sex tape.

The source added: "They've said that they might leak a Kardashian-style sex tape featuring their BB chair romps and call it 'Big Bonker'. I think they were joking."

The couple - who initially appeared on 'The Hills' and have also competed in the US version of 'I'm A Celebrity... Get Me Out of Here' - call themselves the "king and queen of reality TV" and therefore find it fitting to have a throne in their home.

Channel 5 will screen a documentary about the couple, 'Speidi: Scandal, Secrets And Surgery' on Monday (18.02.13) at 10pm.