It's good to help friends find jobs.
Natasha has been unemployed for several months and heard that her buddy Alex's job is looking for entry-level employees, so she asks if she can use him as a reference.
Alex wants to respond to Natasha's question.
Alex tells Natasha he will go a step further and write her a recommendation letter.
Alex tells Natasha that he would prefer she didn't use him because if she gets hired and doesn't do well, it will reflect poorly on him.
Natasha appreciates what Alex is doing for her and it strengthens their friendship status.
Natasha takes offense to what Alex said because it shows he doesn't think she would do well, so she cuts off the friendship.