Living as the Villain's Stepmother

Living as the Villain's Stepmother summary:

The oven exploded while I was baking bread, and I faced death along with my abusive father, who had come seeking me. Then I woke up in a novel I was reading. “I’m sorry, Mo..ther. I’m not hurt.”
In the body of the villainous stepmother “Leila”, who abused the male protagonist “Hirua” when he was young, but was eventually executed by Hirua when he returned as the emperor! In order to help Hirua leave the stepmother’s wraith and live happily, I encounter the Marquis “Lacias Huppert”, who played a crucial role in the original, and proposed a contractual marriage. “Can we have a real marriage instead of a contractual one?”
“Oh, can I sleep with Mother too?” Contrary to the plan to leave only the two of them after a year, it seems that both the Marquis and Hirua have unexpectedly started to become attached to me.