Thunder buddies for life? Not for audiences, at least.

"Ted 2" fans proved shockingly disloyal this weekend, ponying up only $32.9 million for the sequel -- off more than $20 million from what the original "Ted" made ($54.4 million) three years ago over the same weekend frame. It was supposed to give holdovers "Jurassic World" and "Inside Out" a close race for the top spot. Instead, it came in third place, while "Jurassic" and "IO" finished as expected with $54.2 million and $52.1 million, respectively.

In a season when pundits have been routinely underestimating the opening weekend tallies of summer hits by tens of millions of dollars, a movie that underperforms as big as "Ted 2" has to be considered a disappointment.

What went wrong? Here are five possible reasons:

1. The Novelty's Worn Off
A foul-mouthed, pot-smoking teddy bear was pretty funny the first time. The second time? Not so much. "Ted" seems to have been playing on permanent rotation on cable for the past three years, and instead of whetting appetites for a sequel, it seems to have worn out the bear's welcome.

2. Seth MacFarlane Is Wearing Out His Welcome, Too
Since the first "Ted" opened, MacFarlane has hosted the Oscars -- to decidedly mixed reviews -- and wrote, directed and starred in last summer's "A Million Ways to Die in the West," which was universally panned and topped out at $43.1 million -- about $11 million less than "Ted" earned upon its opening weekend.

MacFarlane's not over, by any means (he still has his two long-running primetime cartoons), but his fanbase isn't what it used to be. And few seem to want to see him on camera, even if he is voicing a sentient, pot-smoking bear.

3. The Audience Has Grown Up
Well, sort of.

An R-rated comedy depends on adult viewers, of course, but exit polling shows that only about half of "Ted 2" ticketbuyers were over 25. The grown-ups stayed away, perhaps for the two reasons listed above, and perhaps because reviews for "Ted 2" were much worse than those for its predecessor. Since the over-25 audience actually still cares somewhat about reviews, the pans probably hurt the movie. Moviegoers who've actually seen the comedy liked it enough to give it a B+ CinemaScore, but decent word-of-mouth won't help people see it if weak reviews kept them away in the first place.

4. Fierce Competition
Or at least a zoo, with the poor bear fighting not just genetically-enhanced dinosaurs at the box office, but also emotions inside a little girl's head. "Ted 2" faced the one-two punch of over-performers "Jurassic World" and "Inside Out" this weekend, competition that the first film didn't have to face. A strong argument can be made for "Ted 2's" audience getting lost on their pay to see "Jurassic" and "IO" again.

5. R-Rated Comedies Are Struggling
This summer, anyway.

Four-week old "Spy," while critically praised, is a bit of a slow-starter at the box office. But it's held steady at the box office, boasting small drop-offs week to week, so some of "Ted 2's" fanbase may have got their laughs from Melissa McCarthy instead. Even four-week-old "Spy" may have knocked some of the stuffing out of "Ted 2." "Spy" finished fifth this week, with an estimated $7.8 million, for a four-week total of $88.4 million. That's good considering that it, too, is competing against "Jurassic World" and "Inside Out."

The underperformance of "Ted 2" ends Universal's recent streak of franchise-based hits that it has been enjoying all year, from "Fifty Shades of Grey" to "Furious 7" to "Pitch Perfect 2" to "Jurassic World." While nobody anticipated just how huge "Jurassic World" was going to be, Universal should have anticipated that its audience would be demographically broad enough to steal some of the thunder from its little thunder buddy and shouldn't have positioned them just two weeks apart.

No doubt Amy Schumer is relieved that Universal isn't opening her R-rated comedy, "Trainwreck," until July 17. That'll put three weeks between it and "Ted 2" and five weeks between it and "Jurassic World." After all, those dinosaurs will eat any critter, no matter who created it.