I was looking through his email looking for an email I sent to him previously. And I saw emails from Snapchat saying to confirm his new account and it was a different username than the one I know. I found another email like this. I was able to login into one account and saw he added a bunch of girls but they never replied. On the other account there was only one chat with another girl. What should I do? We've been together for 6 years.

Update: I've confronted him and asked him question but the main answer I get is "I don't know". He says it won't happen again. He also says he forgot about the accounts and he thought they were deleted. It makes me wonder if this was happening throughout our whole relationship.