I'm not telling the OP what to do here, but... How do you think the friend would feel about you later down the line if he finds you that you knew about this and didn't tell him much earlier?
Well there is another side. I once was in this position and I told my friend, I thought for sure he'd send her packing. But he didn't, and instead he swallowed his pride. Well the fact that I knew he couldn't man up made it unbearable for him to be around me, so it wasn't him and his wife that went separate ways.
He really wasn't much of a friend then.
Paul
"I'd rather see a sermon than hear a sermon".... D.A.D.
Trump Won!, Sandmann Won!, Rittenhouse Won!, Suck it Liberal Fuuktards.
