According to eagle-eyed onlookers, Rob and Kristen hit trendy sushi eatery Nobu for their low-key evening out, but tried their best to sneak in unnoticed, with Kristen incognito in a dark hood, and Rob in his trademark baseball hat.
Even still, it came no surprise when the couple were spotted by a couple of lucky fans, who quickly took to Twitter with their star spot, causing the news to spread like wildfire.
'At Nobu in San Diego and guess who is sitting at the next table. Kristen Stewart and Robert Pattinson,' one onlooker wrote, while another added: 'Kristen Stewart and Robert Pattinson are at Nobu a couple of doors up eating dinner. Saw them going in.'
Unfortunately, the attention soon got a little to much for publicity-shy Rob and Kristen, who were swiftly moved to a private room to continue their meal in peace.
They may have been trying to keep a low profile of late, but their names have hardly been out of the headlines.
Last week, the rumour mill went into overdrive, amid reports Robert Pattinson and Kristen Stewart were set to take on the hotly-tipped roles of Anastasia Steele and Christian Grey in the film adaptation of racy novel, Fifty Shades of Grey.
'I think it would be strange,' EL told RedCarpetNewsTV. 'It would just be… uggh! Weird!'
We're not so sure…
Would you like to see Robert Pattinson and Kristen Stewart in the Fifty Shades of Grey movie? Let us know in the comments box below…