A woman has been given a good behaviour bond and told to get treatment after biting off part of her boyfriend's tongue following a night of drinking in Sydney's Kings Cross.

Danielle Lee Hanna, 28, was convicted at the Downing Centre Local Court today of recklessly causing grievous bodily harm and put on a two-year good behaviour bond.

In police facts tendered to court, it was revealed that Hanna and her then 19-year-old boyfriend Jake Collins, had being going out for about three months when they decided to book a room at the Formule 1 Hotel in the nightclub district on May 21.

But by 3.50am the next morning, Mr Collins had collapsed outside Kings Cross Station and was "screaming and screaming for help", police say.

Officers found him lying in a large pool of blood.