How Long Can A Condom Remain Inside The Vagina?

The guy I was seeing thinks I cheated on him because while we were having sex a piece of another condom came out of me. He is rather large and so condom breakages aren't infrequent for us. However the condoms he uses are clear-ish and the piece that came out appeared more opaque (almost like the color of a latex glove). I have not slept with anyone else in several months, so I know it must be from him. However, he won't believe me because I'm not sure how to explain the color discrepancy. Is it possible the piece changed color because of the bacteria or yeast in my vagina? I do think I am prone to latex sensitivity. Also, how long is it possible it was inside me? It was about the size of a nickel or a quarter.