these two things or people will never exist together or agree with each other.

Psychologists believe in therapy, chemists believe in drugs, and never the twain shall meet.

• until you are blue in the face
• up against
• up against someone
• up against something
• up alley
• up and around
• up and coming
• up-and-coming
• up and running
• up a storm
• up a tree
• up for grabs
• up front
• up hill and down dale
• up in arms
• up in the air
• upper crust
• upper-crust
• ups and downs
• upset the applecart
• up sleeve
• up sticks
• up the ante
• up the creek
• up the creek without a paddle