Armin really need to keep his emotions in check, you think he would be less phased to see his past associations…
Like someone said down there, hes probably traumatised. He discovered his bf of 20 years was cheating and he ended up dying all in the same night. He probably didn't even have time to process it...
Ameagari no Bokura ni Tsuite: https://kisskh.at/793184-ameagari-no-bokura-ni-tsuite
And my personal favorite I Became the Main Role of a BL Drama Season 2: https://kisskh.at/783826-bl-drama-no-shuen-ni-narimashita