dating app??

Ok I've been dating this guy for about seven months now and I woke up one morning and happened to notice a blinking blue icon on his phone so I looked to see what it was. I found out it's an app for meeting women. When I asked him why he did not delete this when he met me and we became a couple, he said he just didn't think about it. While i was looking I also found some pics of women and a video too. I know guys look at shit all the time and it would not bother