On the house means it's free, or that the person who says that will pay for whatever you got.
This is not an idiom. When you compare two things by saying one is the other, it is a metaphor. It means that however you keep your house reflects your personality, and vice versa.
It means you do not have to pay for dinner,either it is free or someone else will pay for you. This idiom usually means the 'house' or restaurant owner will pay for not 'anyone'.
In trouble. The image is of your spouse kicking you out of the house and you have to spend the night with the dog.
yes
It is not an idiom, it means your nose is itching.
It's not really an idiom. It means "what are you thinking about."
RFP is not an idiom. It's an abbreviation.
It means to compromise and negotiate. Imagine traveling halfway to someone's house to meet them instead of making them come all the way to your house.
"Sieve" is not an idiom. See the related link.
It's not an idiom. It means the tip of your nostril.
idiom means expression like a page in a book
It means that they eat everything you have in your house