He used to eat his meals OK at set times but has just started to refuse to eat unless he can eat from Tilly's bowl after she's finished even if his food is in his bowl nearby

I've tried feeding them separately but Rupert just refuses and walks off. I can't leave his food down as Tilly seems keen to eat it!
So, I know it sounds mad, but I've felt I had to hand feed him sometimes because I was shocked when the vet recently told me he was almost verging on underweight and needed more food

It's all becoming a stressful event for me at least!
Help...any advice gratefully received.