He showed me his gf's nude!

I don't understand what is happening to or generation. Ok, let's start from starting. Yesterday I was doing something on my phone while walking in my balcony. I was typing something and one of the child (actually one year older then me ) living in my neighbour saw me and commented in a joking way that I was talking to my girlfriend ( I don't have). So we talked a little then he said something about periods, which was disrespectful, so I said that go ask your girlfriend! He just asked me whether I wanna see his girlfriend. I agreed and he directly showed me her nudes. And he was with his friends and they all were completely ok with it because they had seen it earlier many times. Later I told about it to a child who lives on our upper floor and he also said that he had seen it and she ( that boy's gf ) is very sexy. Don't know where are world is heading towards?