Prevent vampire invasion (probably kill too) without garlic / No cheats

Some people know this already, but I just found out recently and could be useful for other people who have not learned about this yet. 

And it is not cheating the game. I feel that this method is rather funny and strange at the same time.

I was playing as a new sim. And as usual the 3rd night I got a visit (invasion) from Vald the old Vampire in the middle of the night while my sim was sleeping.

I was panicking because i was not prepared to defend or prevent, so Vald walked into my bedroom and he successfully drank my blood as usual.

I was mad, did not know what to do, but i wanted to revenge, so I just locked the bedroom door while Vald was still standing in the room. 

To my surprise, he could not leave the room, he was locked inside the room. When my sim woke up, it's payback time, I had my sim fight Vald in the room,

and to my surprise again my sim won the fight (male sim). 

The next night, the female vampire Lilith tried to invade my house while my sim was sleeping (the same sim, the same house, my sim was living alone), while Vald was still stuck inside my bedroom 🙂 , but i moved my bed to another room as i did not want to sleep with Vald. Now with Lilith in front of my house, I managed to lock the front door before she could enter. So she could not enter my house and she left just before sunrise.

Now as i am posting this, Vald has been stuck inside my bedroom for 3 days. He does nothing but singing his terrible songs. I plan to starve him to death inside the room, but since he had a full drink of my blood, so i guess that's a lot for him to survive without feeding for days. Is it possible for a vampire to die from starvation ? Or any suggestion on how to kill Vald who has been stuck inside my bedroom ? I could lure all the vampires into my house and lock them up inside too.