To go to the mattresses = Old gang land saying, which means to gather at the chief's house to fight to the end. It now means to fight to the end.
President Obama must go to the mattresses to save his presidency.
Dial-in = To be well connected
As for teaching, I'm dialed-in on the best methods.
The worm will turn. = A Viet Nam era slang, which means every thing will change.
If you are troubled now, don't worry because the worm will turn for you.
To pimp out = To enhance, to make gaudy or to decorate
Before I could sell my house I had to pimp it out.
To show off = To display
After hard training I usually show off my muscles.
A one-trick pony = Someone who can only do one thing well
Our president can give speeches well. Truly a one-trick pony.
To become antsy = To want to move or change
After a long spell on the train, little children become antsy.
To get something off one's chest = To say or do something that relieves anxiety
The police told the thief to admit his crime and get it off his chest.
Just around the corner = Coming soon
Spring is just around the corner.
A steal of a deal = To get something super cheap
The shop keeper gave me a 50% discount on my shoes. I got a steal of a deal.