You shouldn't grab someone's arm abruptly.
Ulysses is walking down the street when he notices a pretty ladies shoes are untied, and she is in danger of tripping of her own laces.
Ulysses wants to get her attention so that he can let her know about her laces being untied.
Ulysses waves at her to get her attention, and then tells her about her laces.
Ulysses runs over and grabs her by the arm in order to turn her to face him.
The girl is very grateful and offers to buy Ulysses a drink afterwards.
The girl screams at Ulysses's, slaps him, and tries running away resulting in her tripping, falling and hurting herself.