Kevin Federline Claps Back at Sam Asghari's 'Professional Dad' Diss

Kevin Federline ain’t sweating it -- firing back at Sam Asghari’s "professional dad" dig ... and flipping it as a straight-up compliment instead of shade.

Catch our clip -- Kevin shrugs off Britney’s ex-hubby’s jab ... saying, end of the day, being a "professional dad" is exactly what every father should aim for.

Reminder -- Kevin’s held full legal and physical custody of his and Britney’s boys -- Sean Preston and Jayden James -- since 2008 … and he’s been a steady rock in their lives ever since.

The whole convo sparked as Kevin preps to drop his memoir "You Thought You Knew" -- where he’s spilling his side of life with Britney in his own words.

Sam was really just reacting to the tell-all ... joking it could double as the first-ever "how to dad" manual.