Is it sin to have a married wife?
There is no definitive answer to this question, as it depends on your personal beliefs. Some people might say that it's OK to have a waifu who's married, as long as you are not actually in a relationship with her. Others might believe that it is a sin to have a waifu who's married, because it is taking advantage of someone who is in a relationship. Ultimately, it is up to you to decide whether or not you believe it is a sin to have a waifu who's married.