On more than one occasion I've heard the claim that Western European society was often apathetic (as opposed to actively hostile) towards expressions of male/male sexuality during the late 19th and early 20th centuries, with such contact being viewed as 'boys will be boys,' - provided that contact was limited and the males involved went on to have 'straight' relationships. The same claims have said that this attitude disappeared around the early 30s, and was replaced with far greater hostility towards male/male sexual relationships.

Would anyone be able to elaborate on whether this was the case? If so, what factors lead to the changes in public perceptions of male/male sexuality in the 30s?