When characters A and B are facing some danger and character A puts out an arm to protect character B

Good variations:

-Character B doesn’t realize the danger until character A puts out his or her arm
-Character A isn’t the larger or stronger character but still takes responsibility for character B’s safety
-Character A doesn’t stand a chance against the danger
-Character A continues talking like there isn’t anything wrong while standing between character B and the threat
-Character A doesn’t get along with character B and/or vice versa
-The danger is comically minor
-Character A has seemed helpless or bumbling but is now revealing inner depths and hidden strength