An unwanted erection experienced by a
homophobe when they see guys doing something they see as sexually provocative, eg a guy kissing another guy.
The stronger the feelings of
homophobia, the easier a homophoboner is achieved.
This erection is similar to one experienced by a rapist, as the owner of the penis experiences arousal and anger simultaneously. The anger only makes the boner more powerful though, making homophoboners a real hazard for the modern
homophobe.