There is nothing to salvage here - his behaviour shows he has no respect for you, and he probably never will.
This has been dragging on for a tortuously long time, you need to move on with your life.
Honestly, I feel like I've just been a cover for his family because he's not able to come out. I need to address a particular bug bear of mine, and that's you snooping on his emails. You didn't stumble into his email inbox while attacking the laptop with your feather duster. But that doesn't entitle you to snoop on his private communications. Now that the scolding is over, let's address what you did find on your "clean".
Mary O’Conor My girlfriend's husband died very tragically four years ago.
One year later in her mid-20s, she had a liaison with her then boss, resulting in her becoming pregnant. Mary O’Conor My partner is the widowed father of two very young boys.
I don't believe the 'once a cheat, always a cheat' philosophy.
Someone can cheat once in a relationship and never do it again.
Someone can cheat multiple times in one relationship and remain steadfastly loyal in another. What I do think is that once someone has broken that trust more than once in a relationship, that pattern will continue and never end.
You can forgive it once, but once you forgive it twice you are condoning a pattern of behavior. You need to make a clean break and stop the life support this relationship is being sustained on.
In his mind he's got away with it twice, so why stop there? If he wants to sleep around that's perfectly fine - but you're not going to sacrifice your self respect while he does it.
He doesn't get the security of a relationship with the freedom of singledom.
If I were to go off and sleep with someone else it would be unforgivable in his eyes.
But he thinks I should just forgive and forget and move forward like nothing's happened.
The primary reason to keep an online dating profile active is simple: the desire to meet people. Maybe he just likes having his ego stroked when women flirt with him. He may not flirt but likes the idea that women like him. At the very least, this action is a serious sign of disrespect.