my first spanish class

It was last night from 6:30-9pm and I managed to discover and pronounce loudly my first spanish swear word. The teacher was describing the accent ~that goes over 'n's to make it sound very different. So she wrote on the board 'ano' and 'a(~)no'. So someone asked how can you tell the difference, so I volunteered to prononunce them both and discovered that 'ano' is ass in Spanish. The teacher didn't want to tell me, so a student did. As adult learners, I think a teacher should tell us the swear words right from the start so we can a) avoid them and b) know when we're being insulted