Get the head's back up

[Deepurple]

What does "Get the head's back up" mean in the following context?

A mother wishes to fight the unfair treatment for her child at school . However, her friend forewarns her "You need to handle the situation carefully to ensure you don't get the head's back up before you've even started."

And "Ned, Ned, wets the bed." "Now on one (rather pathetic) level that's quite funny of course, but Ned doesn't think so." What do the words in parentheses try to convey?

Thank you in advance.

[Ouisch]

To "get someone's back up" means to put them in an adverserial position, or have them be on the defensive. In this case, the "head" refers to the person in charge of the school. The friend is being advised to discuss the matter of her child's treatment at school in a calm, non-confrontational manner.

"Ned, Ned, wets the bed" is a rather rude taunt, and only people with a mean streak or childish sense of humor would find it funny. That's the "rather pathetic level" being referred to.

[Deepurple]

To "get someone's back up" means to put them in an adverserial position, or have them be on the defensive. In this case, the "head" refers to the person in charge of the school. The friend is being advised to discuss the matter of her child's treatment at school in a calm, non-confrontational manner.

"Ned, Ned, wets the bed" is a rather rude taunt, and only people with a mean streak or childish sense of humor would find it funny. That's the "rather pathetic level" being referred to.

Thank you so much, Quisch.