Why Does 'The Guy She Was Interested In Wasn'T A Guy At All, Vol. 3' Have Spoilers?

Here come the final book in the tales of a gay man series as in the last 2 books some of these are true and some are fantasy

Her life was full of misery and pain until she found out about her mysterious lover on the day of her thirteenth birthday. That person started to take care of her from a distance. What would happen when she finds out her true identity? What would happen when she gets separated from that mysterious lover?

One moment I'm chasing after a rabbit and the next, I'm falling down a rabbit hole! What the heck?! This ain't Alice in Wonderland?! Though as I opened my eyes, I soon found out that I was no longer in my original body and that somehow I transmigrated into the light novel, A Fairytale Romance. And that isn't all, the character whose body I transmigrated into... is none other than the canon-fodder, stuck-up, arrogant, and selfish ojou-sama who was nothing more than a comic relief character, Maria Rosendrey. Life truly sucks...

On the day of our wedding, my fiance Thomas Warsh was killed in a car accident on the way there. His adopted sister rushed toward me, clutching his ashes, accusing me of being a jinx who brought him misfortune. I was drowning in grief when a line of floating comments suddenly appeared before my eyes. [You must remain a widow for three years for your deceased husband. After three years, he will be reincarnated and return to love you again!] [Don’t ever remarry. Otherwise, the male lead will never rest in peace, and you will suffer for the rest of your life!] That was when I learned that my fiancé and I were the hero and heroine of a novel. Only by following the spoilers in the comments and completing the storyline could I reunite with him. I did not remarry. Guided by the comments, I remained a widow for three years, and then another three. However, it was not until I suddenly died from a severe illness that I discovered the truth–the comments had all been written by Thomas. He had faked his death, changed his appearance, married his adopted sister, and fed me endless empty promises so I would continue to slave away for the Warsh family. When I opened my eyes again, I had returned to the day before the wedding.

After I transmigrate into a Gary Stu novel as the evil male supporting lead, a system appears in my mind. It tells me that as long as I can conquer one of the female leads, I will be able to return to my original world with a healthy body. But I've failed in my conquest. There are a few female leads in this novel. There's the fake heiress, Leslie Jackman, who I have grown up with and have viewed as my older sister. The true heiress, Miranda Suller, is a boxer who happens to be seatmates with me during our high school times. My childhood sweetheart, Catherine Langdon, who's also a genius surgeon, happens to be one of the female leads too. Heck, even my own daughter, Natalie Jackman… my own flesh and blood… All of them are quick to fall for Gabriel Linner, the poor yet strong-willed young man who's also known as the Gary Stu of this novel. Because of that, they hate me deeply. The system sighs before telling me that as long as I can die in the hands of any of the female leads, it will let me return to my original world. Later on, I use all of the tricks up my sleeve and succeed in getting killed by the female leads. But why is it that they've lost their minds after I die?

I'm reading a book about a boy who bullies a girl, but they end up in love? Screw that; if it were me, I'd ruin the plot.