My Dad Got An Erection While I Was Sitting On His Laps - A Reader

From a reader

My name is Nkechi . I live at Obollo Afor in Udenu LGA of Enugu State with my father. For security reason, I may want to hide some other details. All I need are good words on how to hand this.

My mother died 10 years ago and since then, father has not remarried. Many have commended him for having endured for this long. But the truth is that I don't think he can hold it any longer. I had tried very hard to make him see reason why he should get another wife but he is adamant.
Just yesterday we were playing as usual because we are very close, I sat on his laps while we were seeing a movie. But to my surprise I felt something hard on my bum...  I felt uneasy but I had to act all normal.

What should I do? Should I talk to him about it?