Giving her a tour of the house that starts and ends in the bedroom. TFM.

This is funny because providing a “tour of the house” is often used by fraternity men as an innocuous pretext to retire to his bedroom with a female classmate he intends to have sex with, since explicit sexual propositions are usually frowned upon in social situations with prospective new lovers and thus a token degree of conceit is expected to be maintained so that the female in question can subtly agree to his intentions while avoiding the outward appearance of promiscuity. The poster is subverting this expected courtship process by offering a “tour” of his house that literally consists solely of his bedroom and dispenses with even the pretense of “touring” other rooms in the house beforehand, which is typically a required step in maintaining the facade. Two hallmarks of fraternity culture are engaging in casual sexual activity, and pushing the boundaries of social decorum to assert one’s dominance. The poster has combined these two practices in a humorous manner.