I watched this movie today. The movie is really fun to watch. Songs are good, picturisation is pretty. Dialogues are crisp. Veteran actors acted better than the lead couple. The movie is fast paced. The word sex is used liberally. You will not find your money wasted if you keep your expectations limited.
In general, logic is not a strong point in movies. But here it looks like a war between friend and fiancee where fiancee is the bad girl. If told from a different narrative, friend can very well be portrayed as villain who tries to seed differences between hero and heroin. Some dialogues are mouthed by heroin to make her look bad, which do not look realistic. Ending is too abrupt. Villain must have at least some shallow or vague motive, which goes missing too.