There are some, for example, BL VN that are NSFW and some are not (I think) because it depends on the characters if they're buff and sexy and there are some that looked totally normal for others like "Ahh, this is a kind of visual novel I know", or something like that wouldn't gross them out. And they tell you that it's 18+ because there will be sex scene or intimidate scene inappropriate to 17 below.
Also, why bring at work when you're working, when you could play it at home, all alone (not saying the house should be empty but in your room alone without disturbance)