Originally, the boy agreed to travel with his girlfriend, but he said he couldn't, saying it would cost too much money.

This situation may be that boys have encountered economic problems or are worried about some aspects of their travel plans. The following are several possible explanations and suggestions:

1. Financial problems: Boys may not be able to participate in the tour for financial reasons. This may be because they don't have enough funds or because they have other expenses to give priority to. In this case, boys can seek other solutions, such as finding travel discounts or choosing more economical accommodation.

2. Poor planning: Boys may be dissatisfied with the travel plan or think that the plan is not perfect enough. They may feel that the travel time is too long, the travel route is not interesting enough, the accommodation is not comfortable enough and so on. It is suggested that men and women communicate more, re-examine their travel plans and try to negotiate a better solution.

3. Unexpected events: Boys may be unable to travel because of some unexpected events, such as job changes and family emergencies. In this case, it is suggested that girls try to understand the situation of boys and re-plan their travel plans.

Whatever the reason, communication is very important. Through full communication, we can understand each other's thoughts and feelings and find the best solution.