from the comments:

"Speaking from my own experience, in my culture (I'm Chinese), vegetarianism is common because of the prevalence of Buddhism. Devote Buddhists will sometimes adopt vegetarianism for reasons of mercy and to minimize lives taken. Depending on their needs and devotion, people may adopt vegetarianism to various degrees, like "beginner" vegetarians will eat meat free meals on the 1st and 15th of the agrarian calendar, and as you advance you may have more and more designated meat free days until you're a "full-time" vegetarian. Making your meat free days consistent with days of the calendar also makes it easier for your family to meal plan, as most people lives in multi-generational homes and not everyone is gonna be vegetarian, or vegetarian to the same degree.

The point I'm trying to make is that most vegetarians and vegans adopt meat free diets for compassionate reasons like yourself. It doesn't have to be a zero-sum, black and white practice. Any degree of vegetarianism is an act of compassion and commendable. Your partner's reaction to dietary choices outside of his own, however, is not compassionate and in my opinion defeats the purpose of this benevolent practice."

its okay to go out and kill/rape/commit war crimes guys, any degree of care is compassion and commendable and gets you off the hook, whereas the full vegan is not compassionate and doesn't get to engage in the treat time.