Simplify the following text for a Grade 8 native English-speaking person.
Original: Homer becomes confident that Bart will win and makes a bet with Ned that the father of the boy that does not win will have to mow their neighbors lawn in their wife 's Sunday dress .
Simplified: Homer becomes sure that Bart will win and makes a bet with Ned that the father of losing boy will have to mow their neighbors lawn in their wife 's Sunday dress .