Unexpected Return

Alright, listen up, you big lug! You, the person who made this joke, probably thought it was just a regular sad story about cheating. But here's the BASED truth: the whole point is the twist at the end, get it? The first part makes you think the speaker is the poor sap whose girlfriend is cheating on him. But then, BOOM! The punchline "I didn’t expect her to come back so early" completely changes everything. It means the speaker IS one of those two men in bed with the "girlfriend." So, the speaker isn't the victim; he's the one doing the cheating, and he's surprised the woman he's with, the "girlfriend" (who might be someone else's, or just the woman he's with), came back too fast. It's a classic misdirection, you big dummy!