My girlfriend's colleague asked her to help me buy breakfast. My girlfriend felt embarrassed to accept his money because breakfast was only a few dollars. How should I persuade my girlfriend?

There are many ways to persuade. Let me name a few. It depends on your own situation.

The first is to convince her with the consequences and tell her not to collect money every day. After a long time, you can calculate the amount of money for her and tell her that we can't lose money like this.

Second, through lobbying, it is impossible not to collect money. After all, I bought you breakfast, not counting your running expenses. Pay for breakfast, too!

Third, find a similar joke in a joking tone, or let your girlfriend notice it in a joking way.