Exaggerated: Every time Bob tries to do anything, Alice suddenly finds herself in mortal danger and Bob has to save her every time.
Downplayed: Bob risked opening himself to Evulz's attack by using magic to create a protective bubble on Alice.
Without Alice's powers, the barren world cannot be made habitable again, even if it is saved from destruction.
As far as Bob is concerned, if Alice dies, the rest of the world just doesn't matter anymore.
Inverted: Bob saves the world instead of Alice.
Gender Flipped: Action Girl Alice has to save the world, but has to stop halfway and rescue her boyfriend, Bob, from being under attack.
Bob apparently attempts to save Alice as a ruse to let Evulz leave himself open, letting Alice die in the process.
Or alternatively, Bob seems to be leaning towards saving Alice until he realizes that if Evulz wins, Alice is just as doomed as everyone else.
He then, at the last minute, saved Alice from death, ruining his plan in the process.
(To the alternate scenario), after Bob says this, Evulz promises he won't kill Alice along with the rest of the world and so Bob saves Alice anyway.
Parodied: Alice breaks a nail during the final battle between Bob and Evulz. Bob sees this, drops everything, and rushes to help her.
Zig Zagged: Alice is apparently in danger, but it turns out that she was manipulating Bob to 'rescue her' from Evulz, who is actually in league with her... but then Evulz discovers that Alice and Bob had planned to have Alice betray him and puts her in real danger.
Averted: Alice is in no danger, Bob lets Alice die, or Bob is fast enough to save them both.
Enforced: "We need to emphasize how much Bob loves Alice."
Lampshaded: "I can't believe I'm doing this... I'll save you, Alice!"