well my ideas are:
Level 1 flex bicep, Level 2 flex pecs, Level 3 dance ,Level 4 feel bicep(worship) , Level 5 strip , Level 6 sex , Level 7 anal
The player will go from level to level by chatting with the girl and learning more about her ( she will feel more safe and secure with him) and of course add some talk at those actions
So ,what do you think?