based texas here here to give you the answer to your worries
it is entirely possible, that in the three years since she pined for the guy, the feelings went away. it is also entirely possible she's riding his balloony pony. you won't know, and juanito won't know. so what do?
nothing.
it's not your problem.
he shouldn't be worried as long as he has no children or is married to her because she's not "his". if she fucks, he fucks off. if she doesn't, then whatever.
the repelling personality trait to women, at least one of them, is insecurity.
why the FUCK should he feel bad that he discovered a woman cheated on him? He was able to figure out she wasn't worth his time, and saves himself further trouble.
>but but what if she was his partner and the love of his life and
then he wouldn't even be entertaining such thoughts in the first place, and your worries about his relationship are unnecessary.
it is wise to put yourself back into the mind of the medieval era men.
you, men, are the ones who have lasting value. you work, you bring money and food and take care of things. if she decides to be a whore, let her. you lose nothing. in fact you gain the opportunity to find a better woman. rejoice.
also tell juan to call his family members to go back to wherever the fuck he is there are too many of them here.