Ketsueki_Hasu
I think Astra wants it straight from the tap. As a way of showing her new girlfriend what she is going to get later or soon. In terms of "loving attention" but having nothing done to her. So her new girlfriend can have that privilege. Perhaps her new girlfriend would like to drink the cream from Astra's mouth. Since the cream that Astra can make still has to be kept secret as her ability is special and unique.