The guy he saw her holding hands with. Was from some pageant. He was pestering her many times to join the pageant. He also forced her to hold his hand a few times. She decided to give it a try to see if she felt any thing with another guy. What he saw was her reaching out to hold the guys hand. After a while she forcefully removed the guys hand. Sad, because if she did feel anything. She would have cheated for sure. So apparently their relationship was getting rocky. She started getting jealous of Ayaka.. Dummy also started ignoring her while talking, and such with that same female friend. No he never cheated on her. She said their date was boring, and canceled in the middle of the date. She then gave him the cold shoulder for a month. He then saw that guy holding her hand after that month.
The pageant guy's intent though. Was to NTR the boyfriend. She told him to get lost, and I think she didn't join the pageant after that.