Pop/R&B song last 2- 5 years, younger female artist

This one is driving me nuts...

- In the video her boyfriend comes home, he's been cheating, song is about him lying to her
- Has a catch phrase that is the title of the song as well, has something to do with the guy talking dishonestly... Lyric "then comes the ....(catch phrase)"
- Catch phrase is something along the lines of "blah, blah", as in she isnt believing a word of what he says
- Beat is one of those pop type r&b type mix beats that Flo Rida's "Low" uses.

Any help would be appreciated, I'm losing sleep over here...

Ke$ha's song "blah blah blah" ?

maybe doesn't totally fit description but i dunno

http://www.youtube.com/watch?v=3taEuL4EHAg

Not Kesha, thanks though