A source close to the couple said: 'Jennifer was over in London shooting her new movie and Brad was also meant to be in the capital for a junket to promote Ocean's Twelve.
'Their time in the UK overlapped by a few days and Jennifer put off doing a lot of things she wanted to do so she could visit them with her husband - she was particularly keen to go to Camden market and shopping in Knightsbridge.
'In the end, though, she did none of these things as Brad was barely in the UK for 24 hours. He flew in on Thursday and left again the next day.'
A Press conference to promote Ocean's Twelve, hosted by Pitt, was abruptly cancelled last Thursday
when fire broke out in the kitchen of the venue, Claridges Hotel.
That night, the couple had planned to dine at Jamie Oliver's restaurant Fifteen with Ocean's Twelve co-star Matt Damon and his girlfriend Luciana Barroso. Instead, they spent the night holed up in their suite at the Dorchester Hotel.
Friends of both have hinted that discussions over starting a family have led to conflict.
Miss Aniston is believed to have wanted to put off becoming pregnant until Friends came to an end.
But the show completed filming at the start of the year and since then she has embarked on three movies.
Earlier this month, Pitt almost broke down in tears on an American TV show when he talked of having children. 'I'm going to say it - kids, family, I am thinking family,' he told interviewer Diane Sawyer.
'Yes, I have got family on the mind. Jen and I have been working something out. Little girls, they just crush me - they break my heart.'
