The rugby star, 28, took a budget flight from Cardiff to Alicante with a group of friends on Sunday night.
'Gavin seemed really subdued,' a fellow passenger tells The Mirror. 'His mates were trying to cheer him up.'
It's thought the dad-of-two is trying to escape media attention after his confirmed split with Over The Rainbow judge Charlotte Church, 24.
The break-up comes only two months after the couple got engaged in Cornwall.
'It was perfect the way it happened - it was a lovely day,' Charlotte enthused after Gavin's proposal.
'It was really awesome, the ring was perfect, he was lovely.'
Charlotte and Gavin are parents to Ruby, 2, and 15-month-old Dexter.
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