Most Americans are familiar with the “base system” baseball metaphor for physical intimacy. If you’re not familiar with it, you might check out this XKCD comic for the complicated version, or this excerpt from baseball metaphors for sex from Wikipedia:
- First base is commonly understood to be any form of mouth to mouth kissing, especially open lip (“French”) kissing.
- Second base refers to tactile stimulation of the genitals over clothes, or of the female breasts.
- Third base refers to groping