Sex sells. Teasing double entendres and coyly posed women have been featured on posters and advertising as far back as the late 1800s. So much so that maybe no one noticed that the artistic male nude also got fair play as a come-hither visual on various ads for motorcars, bicycles, and tourism. As we connect the homoerotic dots we also note that these ads were designed to appeal to men in most cases. While we ponder that, let's also note how easygoing folks were about male nudity in the last century. Not so much today. Hopefully Facebook won't censor this.
Most of the examples below are European posters, long revered for their beautiful design. If you can translate, great, but we didn't.