stomach FAT loose expert-ADVISE?

I had such a fit and medium muscular toned body and i am happy with it. Except my stomach!

Some expert said, sit-up exercise is NOT SUITABLE to loose stomach fat. It it just for SIX-PACKS making. Otherwise (for who has fat stomach), the muscle that you gained from the sit-up, will push your stomach ahead and it will looks larger to the front (fat + muscle). How true is this fact?

Other than sit-up or any kind or exercise (assuming the fact above is true), what is the best way to loose fat of stomach fast? (at least in 1-2 months time)

Expert, please advise.