My dad, 76, has just retired due to ill health, is bored to death, and is also and old bore, racist, sexist and just inappropriate and embarrassing basically. He has now discovered Facebook and cannot contain himself to just "like", he HAS to post stupid and annoying comments on everything and everyone's posts, and seems to love bringing controversial topics (Trump, BREXIT, etc) when the OP had nothing to do with those. How can I tell him to shut up? He has now asked a few of my FB friends to be friends and it is annoying. Grin and bear it?