It is honouring to God to honour your parents, while not ideal you can read the Bible on the train, or have it on the car stereo.
Hypothetically we have to be on our guard against legalism as our sinful nature will tend to legalism rather than grace, just as it will also tend to antinonianism rather than grace.
I think that the key questions is how can you best honour God? If you decide on this basis this then you cannot be faulted for whatever cause of action you take. Whatever you do in true faith is not sin.
For whatever does not proceed from faith is sin
Romans 14:23 (ESV)
With only the few facts in front of me I would say that time with our parents is a wonderful gift from God, and that being a good son is pleasing to God who honours our family life.
At that time Jesus went through the grainfields on the Sabbath. His disciples were hungry, and they began to pluck heads of grain and to eat. 2 But when the Pharisees saw it, they said to him, "Look, your disciples are doing what is not lawful to do on the Sabbath." 3 He said to them, "Have you not read what David did when he was hungry, and those who were with him: 4 how he entered the house of God and ate the bread of the Presence, which it was not lawful for him to eat nor for those who were with him, but only for the priests? 5 Or have you not read in the Law how on the Sabbath the priests in the temple profane the Sabbath and are guiltless? 6 I tell you, something greater than the temple is here. 7 And if you had known what this means, 'I desire mercy, and not sacrifice,' you would not have condemned the guiltless. 8 For the Son of Man is lord of the Sabbath."
Matt 12:1-8 (ESV)