Blimey, I grew up hearing this argument, every summer holiday.
We always went away with my aunt, who was a secondary school teacher. My dad would always start off ribbing her about the long holidays they got, she would respond, and it would end up in full blown rows!
To be honest, any hard working teacher, who does do the marking, do the lesson plans, attend countless staff meetings, attend a good few parent meetings, deal with difficult students, needy students, obnoxious parents etc., would get mightily pissed off with people always mentioning their 'cushy' holidays.
I know my dad would always try to make out that it was just banter, at first, but he knew the reaction it was going to get and he always got it. My aunt always won the argument, but we knew he'd try it again, next year!
By the way, we were at a family party, last weekend, but my brother and sister-in-law had to leave early, as my sister-in-law had reports to finish. She's a maths teacher, but she also runs the drama club and puts on various musical shows throughout the year. I think she works bloody hard and she makes the most of her summer break, which she thoroughly deserves.