Suppose that when two liquids, A and B, are mixed, the temperature after mixing is higher than the temperature before mixing. What does this imply about the forces acting between A and B molecules

If the temperature after mixing is higher than the temperature before mixing, It means that the forces acting between A and B molecules have increased (which is the new intermolecular forces).

There will be increase in the energy (brought temperature increase) required to break the old forces of attraction within each liquid molecules.