All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If Hajj becomes obligatory on both you and your parents, then you have to convince them to opt for one of the following two options:
1. They have to perform Hajj with you. You should explain to them that a Muslim is obliged to perform Hajj as soon as he becomes able to do so. Delaying to perform Hajj is not permissible as established by the preponderant opinion of the Muslim Scholars. Performing it immediately is the appropriate way to follow the Commands of Allah. One does not know what will happen to him; he may become ill, poor, or he may die. The Prophet said: “Hasten to perform an obligation, as one does not know what will happen to him.” In Another narration of this Hadeeth, he said: “Whoever intends to perform Hajj, he should hurry to perform it because he may become ill, or may lose his riding animal, or may face necessities.”
2. They allow you to perform Hajj alone if they are not going to accompany you. Promise them that you will be in their company whenever they decide to perform Hajj in the future.
Allah knows best.