If someone you loved cheated on you, could you forgive them or would there be no path of redemption?

I think about how it mostly goes for someone to cheat and figure it's not just something that "happens".... it takes time for a partner to keep seeing someone else to get to know them and finally do the deed. So, trust was broken when he didn't walk away from a situation before it became more.
To forgive is one thing. To forget is another.
I'm not sure how easy it would be to trust again.
From my own experience.... he fit the ideal of "once a cheater, always a cheater".