At DDs dance practice I usually sit with a dad and chat, he's really nice and always spoke about his wife and family. Yesterday I saw him and he started crying - last week his wife slept with someone at their daughters birthday party, at their house. He said he's not allowed to take her to dancing anymore and that his wife will be. I've chatted to her once or twice before but have no wish to now. AIBU to be polite and say hello if she does but otherwise ignore her?