Title text: factory --- spire --- onslaught --- extractor --- judge
Sketchy is an adjective meaning not thorough or detailed, but which in modern slang is often used to connote creepiness, or a general feeling that something is not quite right. Urban Dictionary provides a good definition of "someone or something that gives off a bad feeling".
In this comic, Randall rates words by how sketchy they make the sentence "Hey baby, wanna come back to my sex ____?" when inserted into the blank. As noted from the scale (which already starts at "sketchy" and goes up to "very sketchy"), the sentence itself is already inherently sketchy, in that it sounds like it would be a pickup line delivered by a person attempting to solicit sex from a stranger.
The sketchiness is increased by the various words which run from the relatively common or understood to the obscure and unusual.
The first few are actual terminology: A sex party or sex orgy are basically group sex parties at which multiple parties engage in sexual activity. A sex dungeon is a location where BDSM (bondage/submission - think leather and handcuffs) activity is engaged in. "Sex House" is the name of an Onion News Network parody of reality shows like Big Brother.
As the scale increases, the words become simply locations where sex might take place, which increase from comfortable to unusual and creepy (i.e. sex crate, sex ravine, sex tarp). It is particularly sketchy because of the phrasing of the sentence which implies the speaker has a specific [insert word] used for sex. It might be sketchy enough to walk up to someone and suggest "let's go down in the ravine and have sex", but it is made sketchier when the phrasing suggests going to "my sex ravine".
The title text continues the thought process with further possible sketchy words, beginning with more odd locations and moving on to "onslaught", an abundant wave of attack or overwhelming amount of something - in this case sex; "extractor" suggests some sort of device that might force someone to have sex; and finally "judge", suggesting the speaker has someone in mind to judge sex. Very sketchy indeed.
- Three of the words in the title text (factory, spire, extractor) are buildings from the real-time strategy game StarCraft.