Chris & Karrueche Back Together

Chris Brown and Karrueche Tran prove ... there really is a fine line between love and hate ... because it seems they're back together.

They two got super handsy Saturday at a charity football game in L.A.

Just days ago Karrueche had nothing but bad things to say about Chris -- and sources close to Brown painted an equally unflattering pic of the relationship.

We also got the former couple leaving the game ... and once again, Chris was openly affectionate.