BDSM is practiced in all social strata and is common in both heterosexual and homosexual men and women in varied occurrences and intensities. The spectrum ranges from couples with no connections to the subculture outside of their bedrooms or homes, without any awareness of the concept of BDSM, playing "tie-me-up-games", to public scenes on St. Andrew's crosses at large events such as the Folsom Street Fair in San Francisco. Estimation on the overall percentage of BDSM related sexual behaviour vary, but it is no longer assumed to be uncommon.