Crossword puzzle clue "they would've been next in this puzzle's theme"

They would've been next in this puzzle's theme

"___ first!" (Editor's note: this would have been a better title for this puzzle)

Number of times this puzzle's theme word appears diagonally in the grid (to complete the puzzle, shade those words plus the Down answers that begin where they meet)

"Something you would cheat on if you knew you wouldn't get caught." "___" (also, the source of this puzzle's theme answers)

First name of a civil rights activist who would turn 85 today, and whose adopted last name is a hint to this puzzle's theme

Where this puzzle's theme pairs would like to meet

Upright, and what's been removed to form this puzzle's theme answers

Theme word inside this puzzle's theme words