I’m having affair with my sister’s girlfriend behind’s husband back… it’s the best sex ever but the guilt is too much

DEAR DEIDRE: I’M married to a wonderful man, have two beautiful girls and, from the outside, my life looks perfect – but I’m harbouring a guilty secret that threatens to ruin it all. I have been having the best sex with my sister’s lover — another woman. She thrills me more than any man has...