Another thing I constantly think about in my SpicyNoodles fic! (Spoilers ahead if you haven't read the whole thing yet)
In chapter 12 "overthinking", Mk worries sick thinking he destroyed Reds life by telling him he loves him, but it turned out to be absolutely unnecessary. But then in the newest chapter (17 "destined"), Mk finds out that he's been unintentionally hurting Red Sons feelings this whole time without realizing it. It's just so sad to me that Mk tried so hard not to make his worries come to life, and still managed to fail by something he didn't even considered to be a worry before. T-T