The couple are on the rocks as he suggests she's a bit, um, thick...
However, it turns out their relationship has hit a rough patch not because of the difference in their years, but owing to the difference in their IQs!
Now’s source says Scarlett, 26, is fed up with the notoriously temperamental actor because he keeps telling her that she isn’t intellectual enough for him.
Sean, 50, who’s campaigned against the Iraq war and helped victims of the Haiti earthquake and Hurricane Katrina, wants her to smarten up her image.
Perhaps that’s why she’s ditched her blonde hair for red?
He’s being really patronising to her and even told her she needed to go to college,’ an outraged friend tells Now.
She was offended by that because she considers herself to be very intelligent – and she’s always hated any “dumb blonde” tags.
‘She’s started to feel he only likes her for her body and doesn’t see her as an equal.
‘Scarlett was pretty enamoured with him but there’s no way she’s going to be with someone who doesn’t respect her.’
Read the full story about Scarlett Johansson and Sean Penn in Now magazine dated 20 June – out now!
SEE PICTURES See Scarlett Johansson at the Spike TV Guys Choice Awards>>