I think he did notice in the last chapter. Because I went back and he was wearing a turtleneck during the sex scene and his body was completely fine before the allergic reaction. He’s just like hmmm.. they looks like old hickies though
So allergic reactions don’t work like you think they do. The MC had those marks around his nipples because of sex with the ML the day before and the marks on his neck are hickys. When the body responds to an allergic reaction to something and results in utica considering it’s being implied that the MC is severely allergic to apples but apparently not enough to be life threatening because we saw no use of an Epi pen and the MC was about to vomit the apples out a little while after- it has to be rightfully assumed he took antihistamines- upon taking antihistamines the uticaria aka hives will usually fade - worst case scenario it takes up to 24 hours but the MC is a healthy young male so that’s unlikely it takes that long. For the marks you see on his body it’s too widely dispersed and around his “feel good spots” for those to be Hives- also we didn’t see signs of the MC scratching- those are just hickys left by the ML
I thought when he saw his nipples he was actually noticing the hives from his allergic reaction now I’m kinda sad. I want the ML to like fully realize how insane the brother is