Got a problem? Write to Deidre here. Every problem gets a personal reply, usually within 24 hours weekdays. You can also private message on the DearDeidreOfficial Facebook page. Follow me on Twitter @deardeidre or write to Deidre Sanders, The Sun, London SE1 9GF (please enclose SAE).I AM having an affair with a girl I met through work just over a year ago.I’m in so deep I feel now I would be cheating on my colleague if I stay with my fiancée – but we have two brilliant kids together.I am not a player. I never meant this affair to happen and I feel very guilty.This girl lives in Wales, I live in London. We work for the same firm and met at a company event. She’s 32 and single.We had to partner up in a workshop and it was the sort where you have to reveal your fears and feelings. It left us talking deeply afterwards and we felt closer.The second night there we ended up in bed and the sex was so moving, it was amazing. We keep in touch through Whats-App and FaceTime and I see her every two months or so.I’m 37 and my fiancée’s 35.We have…