Permission of parents to be a Monk

I already know this much https://buddhism.stackexchange.com/a/35802/17220 Still ,there is a particular case where ,I have no experience/knowledge which is below. Person with 27 yrs. of age and above. Parents are alive. No responsibility over Person. Person is having **exemplary character & is unmarried. Person is unsatisfied by any meditation center , monastery , ashram , yogi etc. ,so want to meditate alone in forest alongside other *religious meditators.** Parents are not ready to accept buddha or buddha's teachings for their child cause they think that it(buddhism) is only to destroy householdness. It tears down parents if person flees away to forest or even tries to do so. **Update** Under these circumstances, is permission required **,if yes ,then how to convince parents.** **Note::** 'To be a monk' means 'to go forth to be' :: detached one , beyond all sense of his own name and form. Without any existence of I, my or mine. Not to grieve if his name and form entity were to decay and deteriorate.