THE DIFFERENCE BETWEEN XLIX

What's the difference between:

1. NERDY AND TRENDY?

2. A movie snack and a XXX-rated movie?

3. An eight-ball need and a seat in church under the AC

Answers:

1. The letter T.

2. The letters PCO - POPCORN (the difference between popcorn and porn)

3. A pool cue and a cool pew