I'll have to give you an example of a post date text from 6 years ago since it's in english, because for the past 6 years I've been living in central america and every girl I've texted has been in spanish thus far.

This example is identical to yours in the form of not making out nor having sex on the first date. In my case, it was the girl that initiated the post date text. However, the response I sent to her would've been the same if I would've been the first to send the post date text. The text is referencing something we were bantering about back and forth during the date, so obviously don't use the same thing unless you also mess with the girl about the same topic.

Also notice how I basically waited almost a day to text her back. That's typically the time frame you want to be in.