I don't know does that have something to do with the matter or not but in Russian culture there was kinda tradition for young women, teenage girls, of "getting ready" for marriage, when they were making temporary girl-girl couple and spent several nights together, with parents consent. I read about it in some books, for example, "Russian Girls" by Irina Shangina, 2007. The book is about traditional cultural and religious viewpoints on women and their roles in Russian society. So I think it could leave a trace and influence on modern attitude in some way )