Context is A weak boy calls his Childhood friend who went Abroad to attend College. She keeps up call and The boy was stunned. Also the girl was Looking like she picked up call in rush when she was doing deed. Then the masculine guy comes, starts fingering the girl then straight up to bed and doing deeds. The boy was still on call, he ended up listening everything. Girl gets tightened whenever the masculine guy whispers korean in her ear while being inside her.
In the end Time skip happens and the girl is with that masculine guy now.