Here's an idea of what Lord Disick is missing out on ... Sofia's slipping into tiny bikinis while on vacay in the Bahamas with her pops, Lionel Richie. If the crystal-clear water, blue skies and soft sand weren't enough to make Scott nostalgic ... Sofia's wardrobe, or lack thereof, oughta do the job.

It's a phenomenon we normally like to call post-breakup hotness, but let's call it like it is ... Sofia's always been smoking hot.

TMZ broke the stories ... Scott and Sofia officially broke up back in August after trying, but failing to work things out, and just last week he hit the beach with a new squeeze with famous parents -- Lisa Rinna and Harry Hamlin's 19-year-old daughter, Amelia Hamlin.