She was amused to find it defined on Urban Dictionary as a term of endearment between siblings. Madame L never would have dared use this word, as a child, to describe or address any of her siblings! She would have had her mouth washed out with Castile soap at the very least.
However, she can think of a few non-siblings she'd be happy to describe, or address, as "Jerkface." And maybe she'll start doing that, soon.
Meanwhile, for her Dear Readers' further enlightenment and amusement, Madame L presents the following, which says it all, now, doesn't it: