Glee is my secret guilty pleasure.  From the show’s addictive storylines to the cast’s  ever-so-catchy covers, I just have to keep tuning into the show over and over again to see what happens next.

So in anticipation of the show’s fourth season (which begins on Sept. 13), a mash-up sung by the cast features the likes of Britney Spears and Justin Bieber!!

Singing Spears’ ‘Boys’ and Bieber’s ‘Boyfriend’ , the song will surely be a hit with the ladies as heartthrobs Darren Criss and Kevin McHale can be heard singing and evidently, melting all of our hearts.

It all comes down to the season finale. Lauren and Heidi have a run in, Heidi’s mom comes to L.A.,and Justin has a shocking surprise in store for Audrina. Will Lauren and Heidi end their Feud and become friends again? Will Spencer make Heidi’s mom cry? All these questions will be answered in “The Hills” Season Four Finale on December 22.

Also, keep an eye out for “The Hills Finale Live From NYC” Pre-Show at 8:00 PM ET/PT. The show will be hosted by MTV News’ Tim Kash and fans will be able to see their favourite cast members walk down the red carpet. The finale follows at 10 PM ET/PT.

If you still can’t get enough of “The Hills,” stick around after the finale for “The Hills” Live After Show. The Pussycat Dolls will be there to perform their latest hit “I Hate This Part” and of course, “After Show” hosts Jessi Cruickshank and Dan Levy will get the reactions from the cast members, and fans will have a chance to ask the questions that are on everyone’s mind.

And in case you want to relive the drama, “The Hills: The Complete Fourth Season” will be available on DVD on March 3. But if you can’t wait that long, order the DVD on December 22 because TheHills.mtv.com is offering fans the option to pre-order the fourth season and receive the DVD set up to three weeks before it hit stores. The first 5000 fans to purchase the season four box set will receive a free limited-collectors disk.