A girl goes to Rome, and takes coins from a magic fountain that makes a few guys fall madly in love with her and follow her back to New York. The rest of the movie is her running away from them and trying to break the curse/spell/magic.
This is one of the worst movies I have ever seen. The plot is dumb. The love story is annoying. The main character is shallow, and indecisive, and needy, and weak. If you need more details just search for “when in rome bad” in your favorite search engine, and scroll through the pages of reviews. Some of them are pretty funny – a lot funnier than the actual movie. Trust me, don’t do it. In fact, warn your girl not to do it. She won’t even like it. The end.