1. I knew John had left work to go to the bank when he wasn’t supposed to, and the boss put me on the spot when he asked if I knew where John was. I didn’t want to lie to the boss, but I didn’t want to get John in trouble either.
2. Their neighbor put them on the spot when she asked to borrow money from them. They liked their neighbor and wanted to stay on good terms with her, but they knew that lending money to a friend frequently leads to disagreement.

Compare to: over a barrel.