They stopped asking when i was 26-27, probably because every time they did, since i was a teen, it annoyed me a lot. When i was younger i used to be very harsh towards them, and one time i shouted to my mother that i was ugly so i will never have a girlfriend, and made her cry. I regret it a lot. Trying to blackpill your parents is beyond retarded. Now i respect my parents (the two only humans i know in this planet, to be honest), absolutely never misbehave in front of them, and try to keep my job so they at least can hold to that: im not a jobless virgin locked in a room. Im a hard worker virgin locked in a room except when i hatv to go to work. Also... the main reason i dont kill myself is because i dont want to make my parents suffer even more. I will do it when they pass away.
I know they are deeply disappointed, but they seem to be accepting, slowly, that im not the son who is going to give them grandchildren.
tldr Dont disrespect your parents unless they are actually evil. Most of the time, they are just worried and suffer because they care about you. Dont make things worse for them. They will accept, sooner or later, that youre an incel. You dont have to convince them about anything. They will know.
