Robert Pattinson and Kristen Stewart -- REUNITED ... Like She Never Cheated

Rob and Kristen were spotted leaving a restaurant with a group of friends Monday afternoon -- never holding hands ... but standing mere feet from each other.

This was the 2nd time in 24 hours they were seen together around L.A. ... just 3 months after Kristen admitted cheating with director Rupert Sanders -- but, even more telling, exactly one month before the release of the last "Twilight" movie. Hmm ...