When your penis becomes erect when talking to a girl, but not because you're horny or want to have sex. Its an erection caused by the good feelings of having a conversation with the girl.
I really like her, but I don't think of her in a horny kind of way. When I talk to her, I get an affection erection.
A gender neutral phrase to describe the intense emotional hard-on that is stimulated through infatuation. It is one of many side effects caused by catching feelings. Infatuation ejaculation typically follows.
An erection which is sprung from a deep appreciation and love for something. This kind of erection is not gender specific, and there is no need to call a doctor if said erection lasts for more than 48 hours.
I have an affection erection for cheaptacos, pizza, or burgers after a long night of drinking.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.