He's jealous of the CAT!!!!!

My boyfriend has just admitted he's jealous of the way I treat our cat. Apparently I give the cat more 'grace' and treat him better than my partner or our 1 year old son?! That's complete & utter bull**** but I'm so angry I don't even know what to say to him. He's just had a massive go at me out of nowhere about it, I'm so confused! Is this normal?! Is it a thing to be jealous of an animal?!! I do love the cat but c'mon...it's a completely different love, and he's my pet ffs! We're in our 30's.. I shouldn't be having this argument should I?!!