Emilia Clarke and Seth MacFarlane end their six month romance 'after struggling with maintaining a long-distance relationship'

PUBLISHED: 17:02 EST, 19 March 2013 | UPDATED: 18:33 EST, 19 March 2013

Game of Thrones star Emilia Clarke and Seth MacFarlane have ended their romance.

The actress, 25, and the Oscar host, 39, reportedly decided to end it over the difficulties of maintaining a long-distance relationship.

A source told E! News: 'They are no longer dating. It was really a location challenge.'

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Calling it quits: Seth MacFarlane and Emilia Clarke, pictured in Los Angeles on September 25, have reportedly split

The insider continued: 'She has been in Europe shooting Game of Thrones and he is based in California, so it was hard to make it work despite the distance. They have remained friends.'

The pair were first spotted together in September and then again at a pre-Oscars party.

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MacFarlane mentioned the romance in a pre-Oscars interview.

'I will say, she is an incredibly kind, supremely talented person and one of the hardest-working people I have ever met,' he said on Thompson On Hollywood.

Going solo: Emilia Clarke arrives at the premiere of HBO's Game Of Thrones in Hollywood on Monday night

Keeping busy: Early on Tuesday Emilia was all smiles as she jetted out of LAX

The Family Guy creator also confessed he wasn't a fan of dating in Hollywood, admitting that often casual encounters can get blown out of proportion.

'It's a pain... because if you date, at a certain point you're in a relationship and at a certain point you're playing the field,' he said.

'It becomes this thing of trying to find places where you can have some privacy, where you're not going to be accosted by people and suddenly linked to someone as if you're in a serious relationship.'