'They were having a really tense conversation and then she just started crying as she was waiting for her food,' a source told the Mail.
'They both looked really uncomfortable and stressed. The chemistry you see on TV just wasn't there.'
Another source added: 'Martha is in a really bad place mentally, and has struggled with all the criticism from her actions on the show.'
Watch Martha wears face mask to Woolies:
The pair agreed to stay together during their final vows on MAFS, despite having doubts about getting involved in a long-distance relationship.
Martha is based in Bondi Beach, Sydney while Michael worked as a schoolteacher in Melbourne until recently.