people can become defensive because you went behind their back and dug into their past.....it clearly shows you have trust issues, or other things....
the golden rule, 'if you ask, then u better be able to take the truth when it comes out'....the past is the past, leave it be.
u keep thinking that they become defensive because they are hiding something...no t always true. you're not looking at this in the correct direction, you have to understand that it offends people when you look into their past....and u expect them to be Mr. Fruity Nice Nice I Wanna P*ssyCat?? nah, it dont work like that....U dont go snooping and get away with it....
if i were u, id go say sorry and ask for forgiveness and leave it be....now if this happened while u two were together, then thats a whole different story....but lets say in 1992, he went to a disco wearing speedos and leg warmers, then yea, thats a beat down fo'sur!!!!