A women and two men are engaging in casual conversation when the woman politely offers food to the men (presumably her guests). Her politeness is mistaken by the men as sexual interest and one of the men follows with crass and threatening innuendo, asking if she is metaphorically offering them a three-way sex act.
However, as in so many XKCDs before, the woman is calm and canny to the ways of nerd culture, even in the face of the rare nerd gang rapist. She immediately acts to remove herself as the focus of the conversation by starting a discussion of vocabulary, insinuating that she is not as smart as her would-be rapists, but that they could educate her. Very few insecure male nerds can avoid the lure of a woman both willing to talk and listen to them, so they immediately begin debating amongst themselves about the coarser points of grammar and vocabulary, struggling for nerd dominance. As they fall into arguing amongst themselves, the woman continues to feed the argument with a quick comment as she slips out the back door and runs for help.