Toecutter

My experience tells me this: If your "friend" does not value his marriage and his family by hitting other shit than his wife, i wonder just how much this individual values your friendship, be careful regarding this guy. If you did not know he was cheating, then yeah, it wouldnt really be your business, but since you know, all i can offer up is that you must act accordingly and follow your gut in this situation. Unfortunately, you friend has made his infidelity your business by informing you about this. When the shit hits the fan, and I guarantee it will, you will be questioned about this. Good Luck. Just my $0.02.

p.s. I am of the assumption that he told you about this. If he didnt and you found out from another source, being his friend will subject you to the third degree.