SEAL LOOKING HOT ... UNDER THE COLLAR

Just hours before TMZ broke the story about Heidi Klum gearing up for divorce, Seal arrived back in L.A. after a quick trip to London -- wearing massive shades, a red scarf, an enormous-collared jacket, and a grim expression.

As TMZ first reported, as of Sunday night ... Heidi and Seal are still living under the same roof.