What Should I Do?

I'm in love with a girl who I have known since university. We were only good friends then because she had a boyfriend during that time. However, she broke up with her boyfriend as she felt the gap between her and her boyfriend was widening. Now, her ex-boyfriend had gone to London to study. He came back here for two months to visit his family and friends before leaving for London again. She still likes her ex-boyfriend and hopes things can work out. She has been going out with him at least once a week for the past month. However, I have also been going out with her on a regular basis. Last week, I gave her a present and a card on which I wrote "A gift of thought especially for you" before I left. Shortly after, she gave me a call and said she liked it very much. I later sent her a message via phone which stated that I don't usually give people presents but I gave this one to her because she is special. She replied with her message, "Ha-ha. Thanks for the gift anyway." For the past week I haven't asked her out. However, I feel that I should do something. Perhaps I should ask her out for a dinner and confess my feelings for her. But, I know that she still has feelings for her ex-boyfriend. I do not know if I should confess my feelings for her now or if I should wait. What should I do?

— Christopher, 25