bahaha, the irony of not wanting to do the work when being threatened with murder versus the willingness to do the work when being threatened with silent treatment 😂
Simply tell them you need to focus on your studies more so you can't let yourself get distracted, especially with Trials & HSC around the corner.
If they give you any grief, there's nothing wrong with telling a teacher. You won't see these people again anyway and they aren't genuine friends so...