Situps, crunches, cable crunches...it's all good. They will make you have bigger and stronger abdominal musculature, which may for a little while make the belly fat look more pronounced. However, more muscle helps you burn more fat and in the end, once you cut down...it's gonna look much better. Besides, stronger
abdominal muscles protect your back from injury.
Even Starr's 5x5 which is really an old
powerlifting routine for football strength and NOT for bodybuilding (although it's damn good for it) includes situps. So yeah, do them or some equivalent exercise.