Counterpoint: Should you tell your parents a lie to make them feel better?

Unequivocally, your answer should be no. The relationship of child to parent is the most important relationship in the world; one in which values, knowledge, and love have been transmitted from generation to generation for time immemorial. A parent is expected to provide a safe and nurturing environment for their children to grow. In return, a child should support their parents to the best of their abilities and maintain a warm and loving relationship with them.
Love, which is fundamental to this relationship, is built on trust. As a kid, you trust your parents to be your guardian, protector, advocate, and provider. Once a child grows up, a parent should trust their children to support them; help them adapt to the changing world, tell them the unaltered truth, and help them live up to the values they provided. If a parent cannot trust their child, who can they trust?
If the parents have set out to be vegetarian, their children should support them in that choice. Obviously, the parents are vegetarian because they have deeply held religious, moral or ethical convictions. A child need only encourage their parents to change values when these values engender harm upon themselves or someone else. Objectively, vegetarianism brings no harm to anyone; in fact, it is shown to be healthier than many North American meat-based diets, more environmentally sustainable, non-harmful to innocent and unsuspecting creatures. In conjunction with any religious reasons, there remains no reason to dissuade one’s parents from this choice, one could argue there are reasons to encourage them.
Vegetarian parents, like all other parents, are fallible. Take Mott’s clamato juice. The bottle is red like a tomato, and the packaging features tomatoes, celery, limes, and, tucked away from the action, one unremarkable shell. Now, this tiny, obscure shell could be easily written off as a stylistic choice. There is very little to indicate that one of the main ingredients is clam juice, which is decidedly not vegetarianism. It’s easy to see how vegetarian parents could mistakenly overlook this.
If the child, who is well aware of the clam components of clamato, saw this happen only once, it could easily be ignored as a minor misstep. A couple of repeat performances of clamato consumption and the child should start to take note. If the clamato juice deluge developed into a habit, the child should immediately alert their parents. To remain mute is akin to betrayal. That would be a lie by omission, and a glaring violation of their trust.
It is best to receive difficult and embarrassing news from those we trust. Strangers and acquaintances do not know us well enough to let us know with just the right context and just the right delivery. Furthermore, when it comes from someone who we trust, we know this news is coming from a place of love, not a casual desire to stir the pot and ruffle feathers. It shouldn’t be easy for us to tell something upsetting to a loved one, because we empathize with their emotional well-being. However, the longer one waits, the more people silently take note of what can easily be described as the parents’ hypocritical and deceitful ways, even if they are only committed out of ignorance.
Unless one hopes their parents remain ignorant of the Clamato clam-spiracy unto the grave, someone, less concerned with their welfare will reveal the fallacy, maximizing the inevitable damage. One would rather have their friend point out the broccoli between their teeth than their boss. Sparing someone’s embarrassment in the present is only kicking the can further down the road.
As surely as time flows, it would be uncovered how the child remained mum over their parents’ mistake. You can imagine the hurt the parents would feel, knowing their child could have told them the cold, hard truth and saved them from misfortune but instead chose to assuage their own insecurities and hesitation. Pre-existing rifts would be repronounced, and the delicate bridge of trust that takes so long to nurture: lurched by the whirlwind of distrust.
One might protest that their parents like clamato juice so much, that the stain on their honour is disproportional to the joy it brings. What kind of joy though, is that built on lies? Once the jig is up, it will crumble like ashes in the cold wind, leaving nothing but the bitter sting of shame and regret, all the fleeting joy poured away like their last bottle of clamato.
You should substitute this temporary pleasure with long-lasting happiness. By telling one’s parents the truth, you are demonstrating just how much you care for and love them. Is not a child’s love sweeter than Mott’s clamato?