Reporter: Ah, celebrity romance, the love that lasts forever. From bad boys to billionaires to bachelorets, there were plenty of fairy tale weddings to go around. Justin timberlake and jessica biel... See More
Reporter: Ah, celebrity romance, the love that lasts forever. From bad boys to billionaires to bachelorets, there were plenty of fairy tale weddings to go around. Justin timberlake and jessica biel got married in puglia, italy. Yes, jessica, for getting married and some little bangs and a pink dress. Get e was jumping all around on that "people" magazine cover. He looks like he's 20 feet in the air. He's literally leaping in the air, he's so happy! And jessica is sitting serenely in front of him sort of like, "does he look like a jackass?" Reporter: From justin and jessica's chateau in italy to a plantation in charleston, south carolina, ryan reynolds tied the knot with his second wife "gossip girl" blake lively. He just keeps getting another gorgeous girl after gorgeous girl. Well, hopefully this'll be the last gorgeous girl. I'm pulling for them. Someone's gotta die with the person they marry, right? Somebody's gotta do it. But if it don't work out, it's another gorgeous girl coming. Reporter: One gorgeous girl took it all the way to the bank. ♪ We are never getting back together ♪ Reporter: Taylor swift's smash break-up anthem of the year "we are never ever getting back together" made breaking-up something to sing about. ♪ Like ever ♪ Reporter: Like her cape cod summer fling with 18-year-old conor kennedy, son of robert and the late mary kennedy, which fizzled after only a few months. I don't know if I hungs out with you, I'd be afraid you would write a song about me. The only time it's been an issue was when I was, like, going through a really bad breakup with a guy, and he's like, "you better not write about this." And I'm like, "oh, I won't." Reporter: Did you? Yes. ♪ we are never, ever getting back together ♪ you might as well watch the movie if you're gonna get the soundtrack anyway. So, yeah, who's she dating? Reporter: But it was the failed long-term relationships in 2012 that were the most surprising. Like amy pohler and will arnett, married nine years. Jennie garth and peter facinelli, 11 years. Johnny depp and vanessa paradis, never married, but together 14 years. AND danny DeVito and rhea perlman hit a rocky road after 30 years. Yeah, it was a bad year for having faith in relationships. Reporter: Including heidi and seal, who famously renewed their vows every year for six years. At year seven, though, things began to get a little itchy. One day you're in, and the next day you're out. Sometimes you're in, and sometimes I dump you. Seal. or Repter: THE SPLIT SEEMED Amicable at first, until rumors swirled that heidi was having an affair with martin kirsten, the family bodyguard. Then seal gets angry saying she's sleeping with the help. Maybe the help told her what she needed to hear. You is kind. You is smart. You is important. Reporter: A lot of people were a little put off by his word choice? It's obviously not true. I never looked at another man while I was with him. Reporter: That may have been true, but by year's end, the supermodel mom has officially moved on with her bodyguard. Don't have a grown man knowing where your wife sleeps. "I just came in to tuck her in and make sure she's safe. Heidi, I'm security. You safe?" Reporter: There was another well-known scandal this year that involved "twilight's" on-screen and off-screen couple. I have a bad habit of under estimating you. Reporter: Rob pattinson and kristen stewart. When news broke that kristen was caught cheating with her "snow white and the huntsman" director, rupert sanders, "twili fans felt like someone had put a stake through their hearts. You don't go and tarnish this epic love story that so many people feel invested in. She doesn't strike me as the vixen. It's hard to be a vixen when you only got one facial expression. Reporter: With a breakup now more public than their four-year romance, kristen fought for her guy. I love you. ♪ I want to be your girl ♪ Reporter: This momentary indiscretion has jeopardized the most important thing in my life, the person I love and respect the most, rob. I love him. I love him. I'm so sorry. Sometimes you just gotta do what you gotta do, especially if you know you were wrong. Yes, you can't be above begging. Baby, please. So robert pattinson takes her back, and at the end of the story, both robert and kristen stewart still look as miserable and sullen as they ever did when they were in love. Reporter: But the breakup of all breakups this year? Have you ever felt this way before? That's how I feel about it! Reporter: The only person who was really surprised, tom cruise. The "tomkat" divorce played out like a hollywood movie, topping the tabloid box office for weeks. This was handled like a navy s.E.A.L. Team's sixth operation. Like "mission impossible." Like "homeland." Find him. Find him fast. It was like something out of a spy novel. She got out of there under cover of night. Katie had to run to new york, of all places. I'd rather be on 42nd street at midnight than with tom cruise. Who would have thought that the scariest man basically in the world is a divorce attorney from toledo, ohio? Martin holmes, katie's dad, don't mess with him. Reporter: A blind-sided t cruise had gone from a married man to a single dad in just 11 days. It happened so quick, in fact, that I didn't even have a chance to pick sides. I didn't even get a chance to pray for little suri. Reporter: From breakups to babies, it was drew barrymore who had a lot to celebrate in 2012. A new husband in june, and baby, olive, in september. Is her middle name oil? Olive oil kopelman. I guess it has a ring to it. ♪ Reporter: One "crazy in love" couple, beyonce and jay-z, added another bizarre baby name to this year's list. We've come a long way, baby! That's right. Yes, we have. And baby, oh, sorry, am i allowed to do that? Do people do that to you a lot? Blue ivy made her debut. Or is it ivy blue? Reporter: Blue ivy, their hotly-awaited bundle, finally made her debut. Or wait, is it ivy blue? Blue ivy, tm. It's been trademarked. Its name is blue ivy, and it already owns a little league team in brooklyn. Reporter: Jessica simpson welcomed her first baby with fiance eric johnson before their big day. We have not set a date. It won't be this year. We haven't had time. Maxwell has taken up all time, and I want a big wedding. Reporter: But with baby number two on the way just seven months after giving birth, let's put a big ol' tbd on that one. ♪ Reporter: They say motherhood really changes a person, and this year it couldn't be more true than for snooki. Where's my boyfriend? Wow. Snooki's a mom! She looked at it, and she's like, "oh, my god, this thing is not nearly as tan as I am." And she realized maybe she's living her life weird. She's no longerling on her face on the sands of the jersey shore. But the fact that snooki is a responsible mother is a great leap in mankind. Next, making headlines, for
This transcript has been automatically generated and may not be 100% accurate.