Does divorce occur if one touches the phone twice without the parents' knowledge, after the father made divorce contingent upon that?

If your father made the divorce of your mother conditional on your holding the phone, and you did what was conditioned, then divorce occurs according to the majority of jurists, whether he intended divorce or threat. Ibn Taymiyyah holds the view that it does not occur if he intended a threat, and he must offer an expiation for breaking an oath (kaffarat yamin). It is obligatory to inform the father so that he counts this divorce and takes his wife back, or offers an expiation for breaking an oath. It is advisable to consult a scholar directly or refer to a Shariah court. If the prohibition was for a reason that ceased, and thereafter you did what you were prohibited from, then the divorce does not occur. The condition is annulled by its occurrence once, unless the wording indicates continuity, such as "every time."