Another question abut TimBob and his...well... TimBobness...?

i made him some hot chocolate... and then spent the next ten minutes trying to convince the boy that it WAS hot chocolate and not coffee (cause A- why would i share my coffee??? and B- as if timbob needs coffee)... and now the kid is taking sips... and spitting them back in... and sipping more... and spitting it abck in... i mean, he's taken in more then he;s spitting out... and he says he likes it... and he just wants to do it that way... so... is there anything i can do to stop this new nasty behaviour of his???