My girlfriend's ability to burp

[wooza]

Advice for the sucking method

It sounds like you’re trying to master the sucking-in method to burp on command, but you’re having trouble with the technique. Here are some tips that might help: Relax and Get into Position: Sit upright and try to relax your upper body. The key is to keep your throat and chest loose. If you’re tense, it will be harder to get the air into your stomach. Lips and Tongue Position: Shape your lips as if you’re using a straw. Your tongue should be close to the roof of your mouth, near your teet…

Look there. I wrote a clear step by step tutorial.