The word "bathos" has always tripped me up; I've been reading it as a sort of exaggerated version of "pathos" -- but is only half correct.
That is, bathos can take the form of overstated sentimentality, but the point is that it's intended to have an incongruous or comic effect. It's a form of satire often used in absurdist or camp humor.
In her essay/manifesto "Notes on Camp", Susan Sontag wrote: "Camp and tragedy are antitheses. There is seriousness in Camp (seriousness in the degree of the artist's involvement) and, often, pathos. ... --- One is drawn to Camp when one realizes that "sincerity" is not enough. ... The traditional means for going beyond straight seriousness -- irony, satire -- seem feeble today, inadequate to the culturally oversaturated medium in which contemporary sensibility is schooled. Camp introduces a new standard: artifice as an ideal, theatricality."
So, where overdone pathos is made to seem unintended in order to achieve its humorous effect, this is bathos.
A fine illustration of this is the bathetic baby duck in "Downhearted Duckling" -- possibly the best Tom & Jerry cartoon ever because it's one of the few that isn't about the cat and mouse trying to (yawn!) kill each other.
Instead, a third character, a duck, is attempting to commit suicide, and the cat is all too willing to assist. It makes me giggle and giggle. (I'm not convinced a mainstream studio cartoon can qualify as camp, but the duck makes an excellent example of bathos.)