I imagine the artist's intention is for Gravel to be saying something like "let's fuck" but it's a case of a Polish equivalent of Engrish?
I think Flametail is thinking about mission/practice/something non sexual since she isnt blushing while Gravel looks at her boobs and all she thinks is "holy shit" Me too Gravel, me too. I never realised this squirrel was so proficient at hiding huge nuts until this day.