The colliding leader meets the eyes of the other leader, acknowledges responsibility by dropping the eyes, and apologizes with a deferential nod of the head. The struck leader meets the eyes of the responsible leader, graciously accepts the silent apology with a nod of the head, then forgives and forgets. If the couple in front in a crowded dance hall fails to start progressing closely behind the couple in front of them, the trailing leader may gently bump himself against the leader in front to alert him, then follow the rules of acknowledging responsibility and apology. Continue dancing when on the floor. Never stop dancing while the music is playing.
Pauses are dramatic elements in Tango best executed with a flourish.
Use a check, a fake, or an ocho to continue dancing while changing direction to avoid a collision. The follower is involved. The follower can see where the leader cannot. Just as a follower can let the leader know she needs an instant longer to complete an embellishment, she can signal the leader to help avoid a collision. She signals by increasing the tension in her frame, resisting going in the direction where she can see that a collision is imminent, or turning her head toward the threat and widening her eyes if another couple seem to be coming up behind the leader fast without his noticing.