You can also discuss things like interests, family, emotional issues, etc.
in greater detail if it looks like things could be headed toward marriage, but caution is always in order as you get more deeply involved.
Also, do clearly discuss limits on your physical involvement (in other words, reiterate that there will not be one) and put methods of adhering to those limits in place.
That said, don't make physical involvement — even a lack thereof — a frequent topic of conversation.
The idea in all of that was not to establish a level of emotional (or certainly physical) intimacy that would imply marriage (defrauding one another), and result in a emotional divorce if things don't work out.