She had a foursome back in the day and now have problems dealing with it even thou it is 8 years down the track

Deal with the person she is today, not the one she was 8 years ago.

When I was single and fancy-free, I went out with a LOT of guys. I honestly can't tell you how many. And I don't regret it, because it meant that when I met my husband, I knew he was the one I was happy to spend the rest of my life with.

When I meet single friends telling me about their wild love lives, I can say "Been there, done that, not doing it again."

What do you mean she has trouble dealing with it? What does it make her do? How old are you? Is it how she acts now, or what she did before that makes you want to break up?

Are you having trouble dealing with it or is it her?

If it bothers you, let her go (break up with her).

If it bothers her, try to help her get over it...

Who is having trouble dealing with it?

I'm assuming you're the one who has the problem with her past.

If you're the one, then you either need to get over it or break up with her. If it's still worrying you after 8 years, it doesn't look like you're ever going to let it go.

We've all done things in our past that we're not proud of, but we don't need someone fretting about it or throwing it in our face for years on end.