This is a tough one. My only suggestion is to make an ‘appointment’ with them. Tell them you have something important to talk to them about. I would be apologetic, no accusatory. Something to the effect of, “This is hard for me, but I found out something and I need to talk to you about it. A man I met at so and so’s house said such and such. I just need to know what is going on.” Use your own words and just be open and non-condemning. I hope this helps!