2,860. "Me, too."

Hilchos Nezirus 2:5

If someone says, “I will be a nazir when a son is born to me,” and his friend says, “Me, too,” the friend is immediately rendered a nazir.

Hilchos Nezirus 2:6

Let’s say that someone tells his friend, “I will be a nazir when a son is born to you,” and the friend responds, “Me, too.” In such a case, the friend is not rendered a nazir. This is because he only wanted to express that he wants a son to be born to him as much as the first person does. He responded as he did because he is embarrassed in front of him.