1. Peggy and Maddie felt sorry about teasing Wanda.

= Peggy and Maddie felt sorry that they teased Wanda.

2. Peggy and Maddie felt sorry about having teased Wanda.

= Peggy and Maddie felt sorry that they had teased Wanda.

(What is the difference between #1 and #2? Is the explanation correct?)

#1 sounds as if they realize they're sorry while they're teasing her.

#2 sounds as if they're sorry after the teasing is over.