Sorry, Justin Bieber, but "Baby" wasn't the most popular song around the "Glee" set this week...it was "Happy Birthday"! On Tuesday, Amber Riley celebrated her 24th birthday with her cast mates, and today their cute co-star Chord Overstreet (who rocked this week's big, Bieber-iffic episode) got all the b-day love. His "Glee"-mates hopped on their Twitter to send 22-year-old Chord (pictured) birthday wishes, including Dianna Agron who posted, "Happy Birthday @chordoverstreet!" and Ashley Fink who wrote, "@chordoverstreet Happy Birthday boo!!!! I love my baby Chord!! Muah!"
Chord wasn't the only one blowing out some candles today. Paris Hilton turns 30 today, and there were plenty of famous tweeters sending birthday wishes her way, including her little sister Nicky Hilton who shared, "There is no better friend than a sister. And there is no better sister than you! Happy Birthday @ParisHilton! xo." Nicole Richie even had sweet things to say, "@ParisHilton Happy Birthday Sil!!" However, our favorite Paris birthday tweet came from Ellen DeGeneres who posted, "Happy Birthday @ParisHilton! For your 30th I'm gonna write 30 things I love about you. I hope I don't run out of space. Here goes. You're pr"
Check out the rest of Thursday's best celebrity tweets, including Britney Spears continuing her "Hold It Against Me" countdown and a "Twilight" star's run-in with Jake Gyllenhaal! Follow us @hollywoodcrush to get even more celebrity and pop culture news around the clock!
@britneyspears Today's the day http://bit.ly/gYpDsp - Britney
-Britney Spears, Singer
@tarynmanning Going to the L.A.M.B show 2night! I hear I get to meet Gwen! I'm kinda really very excited ? hopefully post pic l8tr
-Taryn Manning, Actress ("Crossroads," "8 Mile")
@minkakelly Another gorgeous day of work on #Parenthood! #Ilovemyjob! http://say.ly/pxx93F
-Minka Kelly, Actress ("The Roommate," "Parenthood")
@tinselkorey Went walking. Saw Jake gyllenhaal again... Wha??? LOL Guess I should go outside more 
-Tinsel Korey, Actress ("Breaking Dawn," "Eclipse")
@elizabethbanks Important self-realization made today: I have a lot more Snooki in me than I'd like to admit.
-Elizabeth Banks, Actress ("Role Models," "Definitely, Maybe")
@aus10nichols Oh we will be at Bonnaroo!! With face paint and glow sticks yall. Wouldn't miss it for the world.
-Austin Nichols, Actor ("One Tree Hill")
@khloekardashian Today I think I'm going to be a leprechaun. Who's with me? I'll even have a bowl of Lucky Charms!
-Khloe Kardashian, Reality Star ("Keeping Up With the Kardashians")
@misskeribaby I stole one of my publicist's CRUMBS cupcakes!! Guess that makes me a crumb-snatcher...a happy one. http://twitpic.com/40uf9k
-Keri Hilson, Singer
@mark_salling Whenever I hear little kids speaking a different language I think wow, they're smarter than me
-Mark Salling, Actor ("Glee")
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