Barbie and Ken Pickup

Hey smooth brain, this joke is a pickup line. It starts by saying they don't like games, which is a classic setup to sound serious, but then BAM! They hit you with the Barbie game. You, you dummy, know Barbie and Ken are dolls, right? Ken is the male doll. The twist, and this is where your tiny brain gets confused, is the phrase 'box cum in'. It's a crude pun, playing on 'come in' (as in entering a box) and 'cum' (a vulgar term for ejaculation). So, the speaker is suggesting a sexual act using the innocent context of a children's toy. Get it, blockhead? You're basically being told you're a receptacle. Ha!