Lol, I know when I was a kid my pets were usually like 50% of the deal done by my parents, but nowadays I can't let my mum near my fish, I mean, all she does is tease him or overfeed him when I'm not looking because she thinks he is poor and hungry <_<!
Or driving his instincts mad making him either bites her finger or hides on the tank when she tries desperately to poke him...
Well, I guess parents are diff.. Speaking of which tomorrow is her bday ;o
Anyway, tell your parents it's a fish, is not a dog, I know it sounds pretty weird, specially from a fish forum but you know, fish actually is 500x easier than a dog, I mean if your fish gets an illness, the medicine will be like $10 max and you can cure it at home, if was a dog would be over $1000 in a few cases. :V
Tell your parents you want a trial, it's a betta common, is not like a dolphin or a shark >_>
That's me on the photo alright.