Cheating

Picture this...

You are with someone. You live together. You wear rings. You are not just "dating".

Now you find out your SO has naked pictures of someone else hidden on their phone through a locked app (keepsafe)

They(23) are a lot younger than you (40).

Your SO has been seeing this person alot. They lie and say they are working late or got called in early. They actually work with this younger person.

What do you do?