Legal analysis: not illegal. Generally speaking, a person who has reached the age of 18 is a person with full capacity for civil conduct, and your parents have no obligation to continue to raise you, so you don't have to pay tuition fees.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 1067 If parents fail to perform their maintenance obligations, minor children or adult children who cannot live independently shall have the right to ask their parents to pay alimony. Parents who fail to perform their maintenance obligations, lack the ability to work or have difficulties in living have the right to claim alimony from their adult children.

Article 1068 Parents have the right and obligation to educate and protect their minor children. If a minor child causes damage to others, parents shall bear civil liability according to law.

skill

The above answer is only for the current information combined with my understanding of the law, please refer carefully!

If you still have questions about this issue, I suggest you sort out relevant information and communicate with professionals in detail.