Jennifer Lopez's ass went all "Fatal Attraction" in a tiny pair of tropical shorts ... shouting to the world: "I'm not gonna be ignored." 

The 44-year-old mother of two flaunted her endless legs and famous cheeks while filming a music video with Pitbull and Brazilian singer Claudia Leitte in Ft. Lauderdale for the song "We Are One."

Or, in this case ... two.

The song is the official anthem for the 2014 World Cup in Brazil -- and since it led to us getting this shot ... it's safe to say we're officially soccer fans.