I love cacti. Beautiful amazingly clever plants that can grow and thrive in dry climates, where most plants won't survive. They need those spikes for protection from predators (my phone originally changed this word to pretenders and I am adding it again in parenthesis because it fits the analogy of the people who pretend to love but only want something from you) so I see this as the woman hugging it is a predator (pretender) and the cacti (or prickly person) is very wise to protect itself. 