Are John Mayer and Jen Aniston really back on again? OK! magazine says YES -- and that they had an overnight visit last night!
The mag says Jen strolled into John's Pacific Palisades pad carrying an overnight bag. "Since they started dating, they always -- always -- stayed at Jen's place," an insider says. Before their late night rendezvous, the twosome were spotted celebrating his 31st birthday -- at a cigar bar in L.A.
Cigars and a sleepover... probably as good a way as any to turn 31!