Complex sentence: The club's advisor Emma Pillsbury (Jayma Mays) thinks Holly's lessons are inappropriate, so she arranges for the club to perform a wholesome song for New Directions, picking Starland Vocal Band's "Afternoon Delight", unaware that the song is about sex.
Split into simpler sentences: The club's advisor Emma Pillsbury (Jayma Mays) thinks Holly's lessons are inappropriate, so she arranges for the club to perform a wholesome song for New Directions. She picks Starland Vocal Band's "Afternoon Delight", unaware that the song is about sex.