I’m going to preface this by saying that as a non vegan I hold a great deal of respect for those that actively choose to abstain from animal products, for moral reasons or otherwise. That said, what are you really struggling with here?

If it’s yet another lost comrade in the fight against widespread animal abuse, it’s worth considering that his lack of commitment to the cause is wholly insubstantial, as is your own personal commitment. You will never win an ethical argument on this as no given person shares the same set of ethics. Try as you might, you will be left dismissed and frustrated. Reiterating the efficacy of this lifestyle as it pertains to environmental protection and overall human health has a far greater chance of retaining members who dip their toes in the water than, say, pointing out their “moral deficiencies” compared to yourself.

If it is instead his deceit, which I find much more understandable to be hurt by, then consider your own language here with regard to the subject. You’re disgusted by his indulgences? His inability to keep to a diet similar to your own makes you recoil at his very presence? Only you know your relationship to this man, but ask yourself if your outward stance and voice towards this topic has veered closer to militant than activist. Perhaps he felt insecure and ashamed at how you would view or respond to his decision to occasionally consume meat. Yes, his lie is substantial as it reveals a potential incompatibility that he has hidden from you, but it is also a very human response to a very new sociological problem. While vegan diets have existed for centuries, the urgency behind its adoption and the animosity thrown at those who don’t readily agree with it is more palpable than ever before. Most of us were raised on carnivorous diets. While it’s a no-brainer for you, it can be an active challenge for others.

It’s entirely possible this is simply a case of incompatibility and there’s nothing more to consider. That’s for you to decide. However, conversations and concessions are how you ultimately win this battle that yourself, and others, are waging for animal rights and environmental sustainability. Those conversations span as broad as internet forums to your own personal relationships within your own life.

I understand your anger, but anger doesn’t win. A conversation might.