Tiffani Amber Thiessen is making her latest birthday a memorable one — by posing nude!

The Saved By the Bell alum kicked off her 50th birthday celebration in style on Tuesday with a steamy shot to prove that even though she may be “over the hill,” she’s certainly still ringin’ bells! LOLz!

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The fan-favorite actress posed in bed with just a white sheet wrapped around her as her messy brunette tresses flowed elegantly over her shoulder. She gave the camera a seductive smirk as she captioned the post:

“Over the hill. #thisis50”

Ser (below):

DAYUM! 50 hasn’t ever looked so good!

In the comments, her SBTB co-star Mario Lopez welcomed her to the club, writing:

“Welcome to the 5th level kid!”

Sarah Michelle Gellar also sang her praises, noting that Tifanni “Looks pretty

.” Oh, and The Office’s Jenna Fischer also joined in, adding, “Well done. Starting the 50s exactly right. Happy Birthday!!!,” while Jennifer Love Hewitt sweetly commented:

“Happy Birthday! I remember knowing you as a teenager and hoping to be as gorgeous as you one day! And I still feel the same! You make 50 look great! ”

No kidding!

Reactions, Perezcious readers?? Sound OFF in the comments!

[Images via Tiffani Amber Theissen/Instagram & Saved By The Bell/YouTube]

The post <i>Saved By The Bell</i> Star Tiffani Amber Thiessen Goes Nude On Instagram To Celebrate Turning 50! appeared first on Perez Hilton.