An erection is the stiffening and rising of the penis, which occurs during sexual arousal , though it can also happen in non-sexual situations. Tags Upskirt Public Voyeur Quelle voyeurhit. The ontogeny of social behavior in the gray squirrel Sciurus carolinensis. The adjectival form of the word penis is penile. Webarchive template wayback links Title pop Comics infobox without image. Outline of human sexuality.