antsy
Explanation
The Joke
A woman tells a man wearing a hat (who appears to be an ant or ant-like creature in human form), "Sally, we need to break up." She then asks, "Why? Is it because I'm not conventionally financially attractive enough?" The ant-man responds, "No, it's because I'm actually a trenchcoat filled with ants." The woman pushes further, asking if it is because she is "so weirdly altruistic." The ant-man explains, "She always did so nice things for me, actually -- she kept leaving enormous mounds of sugar everywhere."
The final panels reveal the twist: the woman asks, "Humans don't do that?" and the ant-man replies, "I mean, she did it somewhat..." -- implying that the woman's behavior was only explicable as being attractive to ants, not to a human partner. The entire relationship only made sense because one party was secretly a colony of ants in a trenchcoat.
The Humor
The comic uses the classic "three kids in a trenchcoat" trope -- where multiple small beings stack up in a coat to impersonate an adult -- but replaces children with ants. The humor comes from the gradual revelation that many of the relationship's quirks (the woman's unusually generous behavior, leaving piles of sugar around) only made sense because her partner was not actually human. The breakup conversation plays like a normal relationship post-mortem, but each grievance maps perfectly onto ant behavior. The joke also pokes fun at how people in relationships sometimes ignore enormous red flags -- in this case, the red flag being that your partner is literally a colony of insects.