The [ɔɪ] diphthong. This sound combines the aw as in law with the ih as in sit. Though I have found in practice, as with many diphthongs, that the vowels within this diphthong are not quite so pure as they are when they stand alone. So with the aw as in law, I actually find it to be a little closer to the oh, as in the first sound of no. It does assume the same mouth position, aw, the cheeks come in a little bit and the lips round and come out, aw, law, but rather than saying an aw sound here, it's a little bit more like an oh. And to make that differentiation in the sound, the tongue comes up a little higher in the back than it does in the aw, law, pure sound by itself. Oy, o, oy.
The second sound: the ih as in sit. Ih, ih, oy. I sort feel at times like it's ih with a little bit mix of an ee as in she though it certainly is not oyee, the lips don't come out that far. Oy, oy, oy. So as you can see, o, the tongue is raised in the back more so you see the darkness in the mouth: o, oy... and there you see the tongue come forward for the ih, ih, ih. And the corners of the mouth come out just a little bit.
The boy is annoying. 这个小男孩很烦人。