Evan Ross, Ashley Simpson Hollywood Bowl Diana Ross Concert

Evan Ross and Ashlee Simpson are inseparable!

On Saturday night Evan took Ash to his mom's concert with the Los Angeles Philharmonic at Hollywood Bowl, and X17 photographers snapped the lovebirds on the way out.

The two made their first formal appearance last week at Ashlee's sister Jessica's clothing launch party in New York City, and the first time we ever saw them together was on July 1, when they left the Roosevelt Hotel together.

Think it's true love? Or just a summer fling?