Strangers accusing

Ok so yesterday when I was at the mall with my spouse a man came up to them and pulled them aside for a discussion, I got closer and heard that man accusing him of doing somthing 3 months ago at a conviniant store, he denies he ever did anything. And I want to believe him but this is the 4th time since being married that I have heard rumors and people bring the same situation up. I’m really hurt , not only becouse of the alleged things people say but becouse I feel like I’m being lied to ,I also I feel like I should believe him and take his side .. but from my perspective it seems like he is a liar... I don’t know what to do