Bob and Charlie, while canonically straight, have been known to hold hands, hug, and exchange flirty banter. They are subsequently shipped.
Alice and Carol doing the above with each other, with the same result.
By the fans: Bob and Charlie are simply friends. The fans go wild trying to find subtext in innocuous pieces of dialog between them, and they quickly become the Fan-Preferred Couple despite each of them being part of a Heterosexual Official Couple.
Although Bob and Charlie aren't intended to be any kind of romantic couple, the actors portraying them have clear chemistry and they play it up for a laugh. When the fan-base responds approvingly, the producers decide to just go with it.
The author makes it clear that Bob and Charlie are heterosexual and just close friends, both in text and Word of God, but deliberately gives them a lot of physical closeness in order to get across the message that you shouldn't see homosexual subtext everywhere.
The creator is disgusted and stops interacting with his fandom because of the shipping.
Bob and Charlie live in a setting that is oppressive to gays, and because of this, views any close male/male friendship with suspicion, making it hard for Bob and Charlie to be friends.
Reconstructed: The creator makes up with the fans, and all is well, and includes more Homoerotic Subtext in later epsiodes.
Played For Laughs: Bob and Charlie are actually straight. However, everyone around them is intractably convinced that they're gay, with the result that women that they're interested in reject them because they believe them to be gay, gay men keep hitting on them, and everyone encourages them to take those final steps out of a closet they aren't actually in. This causes them quite a bit of frustration.
Played For Drama:
Bob and Charlie's close relationship cause them both to neglect Alice and Carol, their respective Love Interests. This leads Alice and Carol to leave them, and Bob and Charlie have a falling-out, only to ultimately reconcile and go back to being close, but with added bitterness.