<human>: She knows I slept with other people afterward. What she doesn't know is one of them is a friend I had before the break up and am still in contact with

It was she who ended the relationship and I was heartbroken. When the dust settled, I ended up having sex with this female friend of mine with whom I have maintained a friendship and see occasionally. Considering that this friend is still around and we hang out occasionally [no sex, no feelings (actually)], I know I should disclose this to my girlfriend. My fear is that the stipulation imposed by my girlfriend will be that I cut contact with her. She's been a great friend and was there for me when my girlfriend left. I also would feel uncomfortable with this demand given that she was the one who walked out.

What do you guys think?

Give me the gist of the text in a nutshell
<bot>: Girlfriend broke it off, was heartbroken, picked up the pieces, had sex with friend of mine, still in contact with this friend, year later re established with ex, should I disclose? Break friendship?