Help with Sexuality

Sexuality has three stages:

1. Desire is an interest in being sexual. 
2. Excitement is the state of arousal that sexual stimulation causes. 
3. And orgasm is sexual pleasure's peaking.

A sexual disorder occurs when there's a problem in at least one of these stages.

Adapted from the Encyclopedia of Psychology (http://www.apa.org/pubs/books/4600100.aspx)