My girlfriend was already fully trained (Hayoung and his father)

My Girlfriend Was Already Fully Trained

Left image (Ep. 02): The MC learns that his girlfriend, "Hayoung," is cheating on him; she has chestnut-brown hair.

Middle image (Ep. 22): The mother is worried about the MC, and his father reassures her, trying to downplay the situation; he is already well-acquainted with his son's girlfriend, as he calls her "Hayoung."

Right image (Ep. 31): A photo serving as proof that the mother's husband is cheating. The photo allows for a comparison clearly showing "Hayoung" with her chestnut-brown hair from before she dyed it blonde.

● How long has "Hayoung" been sleeping with the MC's father?

● Does the MC's mother not know what her son's girlfriend "Hayoung" looks like, or does she simply fail to recognize her?

● Will there be more details about this affair—revelations concerning "Hayoung" and the father?

● Will his mother ever find out?