It tears down parents if person flees away to forest or even tries to do so.
It seems person is having very strong bond/attachment with h-is/er caring parents.
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.
That's an obvious reaction from parents who have not been established in dhamma or they are established but worry about person's capability. Even buddha used to question, when his disciple/s want to go to dangerous/full-of-dukkha
places to preach like with the case of 'poorna'.
Moral::
You will have to prove in front of them that you are worthy of independent homelessness.
Under these circumstances, is permission required ,if yes ,then how to convince parents.
Surely, there is a way for someone aspiring to be established on Noble 8 fold path, a 'middle path'.
If parents are very caring, person might start by bearing his own responsibility first, slowly-slowly increasing independent-meditation-time, slowly-slowly showing parents about his/her calibur of asceticness
and decision making capability.
Wait for the right time, start reducing any communication-gap among relation.
No caring parent wants to harm his/her child or to be a cause for any harm. It's just the worriness about safety
that they pretend to act as a barrier
. Understanding them from their perspective will enable person to see/feel them as Helpers in person's decision
.
If parents are not so caring
, then tears
might be out of society-fear but such perception requires one to be very hard-hearted.
In this case, person must make his stand in society first. Person should start by bearing his own responsibility first••• same-as-before ••• decision making capability, ultimately leading him/her to win over everyone's ego.
Wait for the right time, start reducing any communication-gap among relation and society.
With right time and right understanding, person will surely be able to take his/her decision of independent-meditation(asceticness).