I believe the last line happens when your try touching her boobs or ass before bath 2 times in a row.
That's just a guess though by looking at her:
I might be mistaken here but I remember her getting annoyed and saying similar things when you touched her (until
1 AP is spent) two time in a row:
ie:
MC get home and immediately touch her boobs/ass until the first point is spent (She will say something and
1 AP will be spent)
Doing it or a similar thing again will trigger her getting a bit annoyed due to the insistent touching/grabbing and she will actually say that line and another AP point will be spent.
Repeating this process might trigger similar lines as well.
This is as far as I could remember.