The film is about a couple who hit rock bottom and don't have the money to keep their house.. so they decide to start going out at nights to casino's to try and win the money to keep it. The woman is in a very posh clothes shop day having a look when a very rich man gets talking to her as she sees a stunning dress that she would never be able to afford.. the guy then goes onto try and win her over starting by buying her this very expensive black glittery dress. She then agrees to going on a date with him where he take her take her onto a helicopter and onto this massive cruise ship which he owns.. she then goes onto leaving her partner and marrying this very rich man.. the guy that she left then turn into an alcoholic.. whilst she is out going to big posh party's with her new rich man.. this all begins to get too much for her and she starts to miss her partner so she runs away and goes to the place where her and her partner first met many years ago and it turn out her partner is their and they share a very romantic kiss and it ends at that

If anyone knowes the film please tell me! I don't ever stop thinking about it lol

Your description doesn't fit exactly, but there are too many similarities for me not to mention this possibility.

http://www.google.ca/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CB8QFjAA&url=http%3A%2F%2Fwww.imdb.com%2Ftitle%2Ftt0107211% 2F&ei=sp2AULOoFqWUiQLa8oDwDg&usg=AFQjCNGolrVYNYKL8KpP-3QOCpyS-P9csQ

I agree Alty, This was also the movie that came to mind as I was reading the post too. (Indecent Proposel, starring Demi Moore, Woody Harrelson,Robert Redford)

That movie is called indecent proposal with demi Moore and woody harrelson