Is anyone around me using condoms? Site-specific condom-use norms and their potential impact on condomless sex across various gay venues and websites in The Netherlands.

Objective: To investigate site-specific condom-use norms as assumed by visitors of gay venues and websites across The Netherlands and their association with men's own use of condoms.

Methods: In 2010, men who have sex with men (MSM) visiting 18 sex venues (e.g.