The one on the left is the bisexual.

The one on the right is the one that gets offended that people approach her friend instead of her

Oh no bi panic!!!My bidar is so broken

trick question- they both are bisexual

I would ask either one, what answer would the other one give to either the question ‘who is bisexual?’ Or ‘who has the phone that needs to charge?’. It would then always be the opposite of the answer given.