When someone does something so pathetically embarrassing that you would not be human if it didn't embarrass you just through your proximity to the situation.
It is especially potent when you witness this embarrassing act.
Gaby, did you just see that poor girl trip on a banana and impale herself on a hooker's spiky boot?. . . I have such tartingles!
Messing about, fumbling, mucking about: particularly used in the north of England in a derogatory way, to describe some action the speaker believes is not being done properly, or is being done to slowly and inefficiently.