I don't want to be Villainess' Butler VB

The otome game is supposed to start with romance and slice of life, but it shouldn’t end with WORLD END.
I am that one unfortunate child who has been transmigrated into a boy who is designed to be a butler of one unfortunate villainess infamous for her band ends.
Villainess: You are now my butler. How about you let me sit on top of you?
Me: Milady, I am a butler, not your chair.
Villainess: Then how about you catch the ball from your mouth when I throw?
Me (twitch): I am your butler, not your pet…!
Villainess: Then what good use do you have?!
Me: I don’t know, maybe you should learn how to use a butler before hiring (enslaving) one!
Villainess: How dare you raise your voice at me! I am the lady of Grand Duke and your master!!
Me: And I am your freaking butler, not your bitc- slave!!
As you can see, she is a real villainess and troublesome at that. She will soon meet a bad end, and so will I. I have to stop her from meeting those bad ends, or it will be my end.
But…
She also looks… too cute for some reason.
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The first few chapters might be a slight drag and slow, but the pace will soon be picked.
Viewers’ advice: This is not for people who want Gary Stu or Mary Sue in the story. I will make them a little realistic, and plot armor will not be on MC’s side. MC has severe case of PTSD as former US soldier so he will not kill his enemies in early chapters until his trauma heals. If you are not okay dealing with it then please take your leave. You will be wasting your time.