Caught my teacher doing a student?

Ok, so yesterday I’m having basketball training after school. So I realized I forgot a water bottle at my history teacher’s room, so I went to get it. I realized the door is locked, and the windows and shades are down, so I can’t get in. The doors at my school have a small narrow rectangular glass pane on it, so you can see inside. At the corner of the pane, I can see my teacher “doing it” with my female classmate. I heard him moaning how he *** inside her and she might be pregnant. Should I tell?