Heard my best friends' wife having sex while he was at work! What to do?

I've been going crazy since this happened last weekend. My buddy is selling a really nice and brand new set of golf clubs, and on Saturday I had a last minute opening for a teetime, so my buddy left his garage open so I could try his out. While I was in the garage, I heard his wife having very energetic and enthusiastic sex, and there were two guy's voices yelling and groaning and all that. I know that my friend was at work, though. Anyhow, while I was sitting there frozen, I noticed that the 4-iron is slightly bent. My friend wants $600 for the clubs, but with the bad 4-iron, I can't see paying more than $400. What do you think I should do?