How to manage bedtime stories with multiple different aged kids?

Reading is big in my house. I spend about an hour a day working with my 6 year old after school and I have my son 10 read a minimum of 2 chapters after school. My conundrum comes at bedtime. I read my 6 year old a story every night and have her yoto set up so she can play a book while she falls asleep. The books I read to her are appropriate for her age but too young for my son. I used to read him a chapter every night at bedtime from whatever book he is currently reading but it became unmanageable and made bedtime take hours due to reading/discussing (and he is really good at getting me talking). And to be honest I just don't have it in me to spend hours on bedtime (showers/teeth/reading ect). Tonight he was hitting me hard with wanting me to read to him but I told him he was welcome to read BEFORE bedtime but we were already 30 minutes past bedtime and I would not be reading to him. He hit me hard with the " you always read sister a story every night". I feel extremely guilty. Am I handling this wrong? Do ya'll read multiple books a night when you have split age kids? Am I wrong for not reading to him at night like I do my 6 year old because he reads on his own? 😪