The 30-year-old DJ - who announced earlier this month he had ended his year-long relationship with the 'I Will Never Let You Down' star - reportedly felt the singer was being too vague about her whereabouts after they flew into the US for separate visits at the same time, and Calvin was left furious when he coincidentally used the same driver as his then-girlfriend.
A source told The Sun newspaper: ''It all ended when the driver suggested to Calvin that he had taken Rita to a hotel two days earlier instead of driving her to stay with him.''
The 'Acceptable in the 80s' hitmaker was said to be suspicious that Rita had even hidden in her make-up artist's hotel room for the day to avoid being photographed in public, which would have alerted Calvin to her presence.
It was recently claimed that Calvin announced news of the split on Twitter before he even told Rita, 23, herself.
A source said: ''Rita was left embarrassed when he tweeted that it was all over.
''She didn't think he was going to make the announcement, so she was shocked.''
'Smalls Change (Meditations Upon Ageing)' arrives in April.
The two awards have made for a great 72nd birthday present for the country music icon.