My partner got a message at 11.50pm via Facebook messenger from a woman he originally said on an early occasion was just a cleaner from work. When I asked him why she was messaging him so late at night he said she was just a friend and there was nothing to it so I asked to see her message if it was innocent and he refused to show it to me, firstly saying he had deleted it and then that he hadn't but still he wouldn't show me. She also has been commenting on his statuses on Facebook in an overly familiar way and I just wondered if I am being unreasonable to want to see her messages or to ask him about this again. We don't live together and i have also noticed that he is on WhatsApp and Facebook until around 4am each night.