my husband added "porn stars" to his snap chat

For those who aren't familiar, you can follow people on Snapchat like you do on instagram or facebook. My husband and I have been married for 4 years and together for 10 years. I'm 27 and he's 29. He has a very high sex drive and we are pretty open with the idea of finding others attractive and I am aware and okay with the fact that he looks at porn and masturbates at least a few times a week. (But I have no idea to what porn or when etc). 
He has joked about following porn on Snapchat stories before; and today he told me he started doing it then laughed and said he was kidding but ran to his office to start deleting them from his follow list, but I feel like he took it too far. Snap chat was a place for us to share our lives with friends and family. I'm really just hurt and disappointed. The girl that he let me see before he deleted it was not a fake porn star look but a girl next door grabbing her boobs in the shower etc. 
Am I being too harsh or would others be hurt by this too? 
Update: I'm not "okay" with him watching porn nor do I condone it, but I have accepted that he likely does look at something from time to time due to finding porn on his browser history when I was younger and putting up a boundary for myself not to go looking for it anymore. On Snapchat what probably bothers me the most is that he is carrying around videos and pictures that girls post throughout the day getting naked etc.