My Girlfriend Keeps Speaking To Her Ex

I have been with my girlfriend for 15 months and known her for 18. I love her with all my heart and I'd do anything for her.
She was with her ex-girlfriend for 3 years (on and off) and dumbed her about 5 months before I met her. Her ex-girlfriend cheated on her 7 times and is a complete ***** (excuse my French).

Anyway.. The first 10 months or so I was with her, she did not speak to her. Sometimes she went on her Facebook to see what she was up to (they are not friends on there btw). And on her birthday and christmas the ex wrote to her, she did not write back.
After the 10 months we had a big fight and they spoke together. We have cleared out the argument, but she keeps speaking to her. They have rung together a couple of times and they keep speaking on Facebook. I have made it clear many times how uncomfortable it makes me feel and I would prefer if they didn't. But I cannot force them to stop.

Last time they wrote together on Facebook my girlfriend asked her to get Skype so they can talk. This is completely out of order and I told her that. Her response was just: Oh she'd never get it anyway.
But here we are, 4 days later, both with Skype.
She, my girlfriend, said that the ex added her and told her to accept. I have a feeling it was the other way around, but it doesn't really matter because she still accepted or added. Both equally bad.

Every time I come near her computer, she turns the screen away or sits somewhere else (always with a lame excuse). When she leaves the room, she logs off Skype.

Is she hiding something from me?

Does she still have feelings for her?

What do I do?

She tells me to trust her, but it pains me. I don't want to start an argument, and to be frank I really thought she'd stop speaking to her by now.

What should I do?
An Ep User An EP User
Jan 21, 2013