My wife often visits the grave site of her former boyfriend who she dated for around 10 years. He was also very close with my in-laws. Initially I wasn't opposed to it for we weren't married. However, since we are now married I expressed my displeasure with this matter and also the fact that she has a few plots next to his which I also object to. Am I wrong for telling her to cease the visits and sell the plots and being displeased by the feeling of quasi loyalty toward me?
You are jealous of a dead man. It is because he died that his girlfriend became your wife. But jealousy as an emotion is something that can easily get out of control. "Wrath is cruel and anger a torrent, but who is able to stand before jealousy?" (Proverbs 27:4). It sounds to me yours is reaching a point that it will destroy your marriage.
This isn't about loyalty to you. This is about her grief and keeping memories alive. For all I know, she might be wrestling with guilt over why he died.
"Love suffers long and is kind; love does not envy; love does not parade itself, is not puffed up" (I Corinthians 13:4). You knew she was strongly attached to her boyfriend prior to marrying her. Nothing has changed -- marriages don't change people. You accepted who she is when you married her.
Overtime, if you work at it, she'll have the good memories of her marriage to you to fill up her life. In the process, the memories of her boyfriend will become less important to her. But the point is that she will choose to let them fade because she has something better.
So quit competing with the memories of a dead man, and continue to build loving memories of someone alive who is there for her.
Thank you for your response, brother. I failed to recognize this from my perspective. Jealousy is something I need to address. It's amazing how the scriptures can humble and change my very thoughts and ways. May God continue to bless you and this work.