How did Tom use his tardiness to win Becky Thatcher’s attention?

Tom's punishment for tardiness (in addition to being whacked) is to be sent to sit with the girls. Tom is elated, gets to sit next to his crush (Becky), and even has the chance to pass her a note declaring his love. He couldn't have asked for a better punishment, except for the fact he got caught in the midst of his flirting (Becky slapped his hand), and as a result he was sent back to sit with the boys.