Bowser is just head over heels for you, at first he mistook you for being Peach when your just her maid

then he just apologize and continue chasing Peach, but he started noticing you more often

He was confuse when your kind towards him, he thought you hate him for stealing your Peach but you only beg for him to not hurt her not like he will

Until he told you he will stop chasing after Peach and when he saw your smile he blushed "Dont be so happy I just got bored of chasing her okay?"