Kinda unrelated and trauma dump so read with caution
but this explanation remind me of my dad. So basically i live all my life thought that i had O type blood because my father is O until i donate my blood and turns out it was B. I when home and told my family they always thought i was O too and my dad suddenly when defensive about how theres no way i was B type and act like my mother had cheated. Eventhough my mom is B too. I was so baffled by his reaction over it. I tried explain about blood type but he still argue with me but later never brought it up again after being proven wrong.
after reading this remind me of the similarities because he was a notorious cheater since i was a child and hence why he immediately act as in my mom cheated too.
reminds me that there were rumours of cheating in my family bc of wrongly taught eye colour genetics ("2 blue-eyed ppl can't have a brown-eyed child") lmao, that said i know a girl finding out about her true dad by being able to roll her tongue while both parents couldn't, which is also not necessarily how those genetics work
sad to hear about your dad tho
do dna tests not exist in japan lmao the dad left for no reason