"Fifty Shades of Grey" whipped the box office into shape this weekend, but how long will Mr. Grey's tutelage last?

Sam Taylor-Johnson's adaptation of the best-selling E.L. James novel took in an estimated $81.6 million over the three-day weekend. It's expected to come very close to the $100 million mark for the four-day.  This weekend's result, however, is the fifth largest R-rated opening of all-time behind "The Matrix Reloaded," "American Sniper," "The Hangover Part II" and "The Passion of the Christ."  While "Grey" may be critic proof it's still not clear if its audience proof. The movie scored a very weak C+ Cinemascore which means word of mouth may not help it past its core fan base. That being said, "Grey" is still a major hit for Universal Pictures and its already earned a smashing $158 million overseas.

Debuting in second place was Matthew Vaughn's "Kingsman: The Secret Service" with $35.6 million and it should earn over $42 million for the four-day frame.  That was actually a much stronger result for the 20th Century Fox release than pre-release polling indicated.  "Kingsman" also looks like a legitimate hit although it needs to continue its strong early run overseas to make up its reported $81 million production cost.

Last weekend's no. 1, "The Spongebob Movie: Sponge Out of Water," dropped to no. 3 with another $30.5 million and $93.6 million in just eight days.  The long awaited sequel has already surpassed the original's $85 million tally back in 2004.

"American Sniper" continued its stellar run in fourth with $16.4 million and an amazing $304 million so far.  "Sniper" was actually down only 29.4% weekend to weekend so at this point a $350 million final cume is not out of the picture.

"Jupiter Ascending" rounded out the top five with another $9.4 million and $32.5 million to date.

Sony Classics' "Still Alice" upped its theater count to 502 taking in $1.7 million or a good $3,414 per screen for $4.6 million to date.  It will be intriguing to see how much of a boost the indie will get in theaters after star Julianne more takes home the Best Actress Oscar a week from today.

New releases on Friday include "The DUFF," "Hot Tub Time Machine 2" and "McFarland, USA."

With over a decade of experience in the movie industry, Ellwood survived working for two major studios and has written for Variety, MSN and the LA Times. A co-founder of HitFix, Ellwood spends his time relaxing hitting 3’s on the basketball court and following his beloved Clippers.