As long time Spidey-watchers have long noted, Peter Parker's justification for concealing his secret identity from his family( esp Aunt May) is that given the latter's heart problems, the shock of discovering that he is really the "public menace" Spider Man , could be so great that it might induce a fatal attack on her part.( Given the medical condition known as Takutsubo- "broken heart syndrome"- in which any overwhelming emotional disturbance could cause a seizure this is hypothetically possible)

Well, when she really DOES uncover his secret, May is naturally deeply surprised but shock horror, she does NOT drop dead clutching her heart( she may NOT have known that he was really Spidey but she always suspected that he was hiding SOMETHING- even if she mistakenly suspected him of being gay at one stage)-, proving that May Parker (nee Reilly) is one tough old bird!

Terry