When I first started writing romance, I became aware that there were certain behaviours endemic to all cultures and time periods.
I knew that one of the patterns of behaviour had to do with courtship ritual and the way people behaved when they were attracted to each other, so I went in search of body language. In Peoplewatching by Desmond Morris, I found my answer.
There is indeed a sexual sequence that people display when courting. The length of time spent on each step depends on the culture. For some very conservative cultures, weeks or months may be spent in the first few steps; for other cultures, the first steps may last a matter of minutes. But unless it is a case of rape or prostitution, people do not go directly from the first step to the 12th step.
The sexual sequence is important for the writer because if she starts missing out steps, the relationship can fill off some how. At each stage of intimacy, partners can abandon the courtship if they so choose. If they are not allowed the choice (implicitly or explicitly), the later stages can feel forced and can leave a nasty taste in some readers' minds.
Equally, depending on the sort of story one is writing, the knowledge of the sequence can enable the writer to concentrate on certain aspects. For example, a writer of sweet romance will probably be writing sensual scenes that mainly deal with the first six steps of the sequence, while the writer of a spicy romance will perhaps concentrate more on the last few steps.
Couples can agree to forego certain steps, but this generally happens when they are known to each other and have experienced the entire sexual sequence before with that partner.
So here are the steps:
1. Eye to body: This means seeing the person, but it also means seeing the warm or open gesture that that person makes. People use body language to show that they like someone or are receptive to advances.
2. Eye to eye
3. Voice to voice: The tone can be important.
4. Hand to hand: This is an important step as it is the point of first physical contact. It is also can be disguised as a supoort, directional guidance or body protection. In other words, it does not have to be overt.
5. Arm to shoulder: This can be simply the helping on of a coat but bodies are closer.
6. Arm to waist: Closer still and the hands are now nearer to the sexual regions.
7. Mouth to mouth: The first kiss.
8. Hand to head caress
9. Hand to body
10. Mouth to breast: This implies that the couple are now in skin to skin contact and are exploring each other's body.
11. Hand to genital
12. Genital to genital
You can see the sexual sequence allows for a wide scope of variation and that couples can choose to linger at certain stages or even retreat back to other stages, but ultimately the most successful romances will show a progression through the stages.
For more on body languages and its use in cultural behaviour, I do really recommend reading Peoplewatching.