The dumb question takes ten seconds. The dumb mistake takes the whole semester.

Embarrassment from asking is immediate, visible and brief. The cost of not asking is delayed, invisible and much larger, which is why the trade keeps getting made the wrong way around. Your head compares a certain small discomfort now against a vague possible one later, and picks the vague one every time. Written out, the arithmetic is obvious.

Ask the question you are sitting on, ideally today, and if the room feels wrong then afterward or by message. Nobody remembers who asked what by next week. The thing you would have gotten wrong for three months is the part that would have lasted.