Pomelo — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
Citrus oils again. Flesh in tiny amounts only.
The full verdict, portion guidance and serving notes are collected on the Pomelo food facts page.
Short answer
It's not an emergency, but you should keep a close eye on the cat that ate the pomelo. Citrus flesh is only mildly irritating to cats and a tiny amount is usually tolerated. Watch for vomiting, diarrhea, or signs of stomach upset over the next few hours. If any of those symptoms develop, give your regular vet a call.