Communication and trust might be lacking in their relationship rn, but the ml's petty excuses of being busy and not reciprocating the "ily" message is just mess up. Dude really said "i know" like he's some cold mf and not the dude who chased mc in the entire story.
I also hate when author do this kinds of twist near the end of the story (is this the end or ??) it feels force or out of place, it's like its just there to give conflict for this couple just to make them more "real". Again my opinion.