Push It by Salt-n-Pepa is featured in Showmance, the second episode of Season One. It is sung by the New Directions.
Originally, the New Directions are supposed to perform Le Freak at the assembly, but the kids believe that it is too old-fashioned and will deter students from joining instead of winning them over. This is why Rachel suggests to perform a number that gives the students exactly what they want: "sex." They don't inform Will of this, however, and while the number seems to be well received by the students, it causes Figgins to present Will with a list of pre-approved songs that the club is allowed to sing, songs which all either have "Jesus" or "Balloons" in their title.

Lyrics:
New Directions Boys:
Ah, push it
Ah, push it

New Directions Girls (New Directions Boys):
Get up on this!
Oooh, baby, baby
Baby, baby
Oooh, baby, baby
Baby, baby

Get up on this! (Ah, push it) (Mercedes: Hey!)
Get up on this! (Ah, push it)
Get up on this! (Tina: Sa-Sa-Sa-Salt and Peppa's here!)
Get up on this! (Rachel: Sa-Sa-Sa-Sa-Salt and Peppa's here!)
Get up on this!

Artie:
Now wait a minute, y'all
Now this dance ain't for everybody
Only the sexy people
So all you fly mothers
Get on out there and dance
Dance, I said!
Holla.

Rachel (with New Directions Girls):
Sa-Salt and Pepa's (here)
And we're in effect
Want you to (push it, babe)
Coolin' by day
Then at night (working up a sweat)
C'mon girls (let's go!)
Let's go show the guys (that we know)
How to become (number one) in a hot party show (now push it)

New Directions (New Directions Boys):
(Ah, push it) Push it good
(Ah, push it) Push it real good
(Ah, push it) Push it good
(Ah, push it) P-Push it real good (Ah, push it)

Artie:
Uh Uh Uh Uh Uh Uh Uh Uh

New Directions Girls:
Get up on this! (Mercedes: Hey!)
Get up on this!

Finn (with New Directions Boys):
Yo, baby-pop
Yeah, you, come here (Gimme a kiss)
Better make it fast
Or else (I'm gonna get pissed)
Can't you hear the music's (pumpin' hard)
Like I (wish you would?)
Now (push it)

New Directions (New Directions Boys):
(Ah, push it) Push it good
(Ah, push it) Push it real good
(Ah, push it) Push it good
(Ah, push it) P-Push it real good (Ah, push it)

New Directions Girls (New Directions Boys) :
Get up on this! (Ah, push it)
Get up on this! (Mercedes: Aww!) (Ah, push it)
(Artie: Holla) Get up on this! (Ah, push it) (Mercedes: Hey!)

New Directions:
Aaaaahhhh
Push it!

New Directions Girls:
Oooh, baby, baby
Baby, baby
Oooh, baby, baby
Baby, baby

Mercedes with New Directions Girls:
Boy, you really got me going
You got me so
I don't know what I'm doing

New Directions Girls:
Oooh, baby, baby
Baby, baby
Oooh, baby, baby
Baby, baby

Mercedes with New Directions Girls:
Boy, you really got me going
You got me so
I don't know what I'm doing

New Directions (New Directions Boys):
(Ah, push it) Push it good
(Ah, push it) Push it real good
(Ah, push it) Push it good
(Ah, push it) P-Push it real good (Ah, push it)

New Directions Girls (New Directions Boys):
Get up on this! (Ah, push it)
Get up on this! (Mercedes: Aow!) (Ah, push it)
(Artie: Holla) Get up on this! (Ah, push it) (Mercedes: Hey!)

New Directions:
Aaaahhhhh!
Push it!

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