greasemonkey – Youtube – does not show the context menu on the right button

The idea: search Youtube video by dragging and dropping the video player with the right button (for example, 1 second for every 2% of screen width). Then, on a 1920×1080 screen, if I press the right mouse button, drag some 384px (20%) to the left and then release it, the video should rewind 10 seconds.

I have a GreaseMonkey script that does almost what I want, but the context menu still appears when I release the button. This is not the default context menu, but the Youtube custom contextual menu, which is presumably somewhere linked to the mouseup event. I want to get rid of this menu, and I also want to avoid opening the default context menu.

Is there any way to change the default actions in the mouse events? I want to keep all other actions (left click, keyboard actions, etc.). I have not found a way to remove the event handles in an element for a specific event.

if (window.top === window.self) {
// The YT video can not be manipulated from the scope in which GM is running
// then we add a