Martin, 33, let a number of homeless people perform with him during a recent show in London and he preferred to hang out with them instead.
A source said to UK newspaper Daily Star: 'Chris had a load of homeless people singing in a choir for his gig and he thought they were so amazing he wanted to hang out with them after.
'He went backstage, snubbed his celeb dinner and ordered 12 giant pizzas and 25 bags of chips for them all to eat.
'His security were desperately trying to get him to leave and go back to his dressing room, but he was having none of it.'