JOHN INVITED JEN ON TOUR

The JENNIFER ANISTON/JOHN MAYER romance just got hotter by a notch - John's invited Jen to join him on the first week of his European tour this summer and she's happily agreed, say insiders.

CAUTION, JEN: That's how John and JESSICA SIMPSON broke up - she joined him on a tour, then got all clingy and high-maintenance while he was crazy-busy doing rehearsals, sound checks, press interviews, etc. …ending their love song on a sour note.