That is what I like about you Nic you are both subtle and smooth. 
There may be cultural difference at play here but there is no doubt at all that in Australia, it means what TLD said. When I was a kid I used to see the sticker on vans as TLD describes and asked my parents insistently what the sticker meant and was puzzled when they wouldn’t give me a straight answer. I had to have it explained to me by an early teen’s normal reliable source of information on such topics: friends who had older brothers.
Thank you my friend. It seems so few recognize that about me.
Hey, there’s nothing wrong with showing your great tits.
I for one have never seen them both at the same time. And I’ve been to a lot of biker bars.*
*I haven’t been to a lot of biker bars.