Going off their ages and genders I'd say the worst thing that will happen is your house getting trashed from them constantly playing and arsing around.
I've kept axolotls, clawed frogs, horned frogs and a leopard frog before but I always fancied an African or American bullfrog. Is it Pixicephalus adspersus the Latin name? Big green thing that eats everything. My missus is terrified of frogs though.