how bout an awkward moment

During the week I work at a school, and a few days ago we had a fire drill.  I knew it was coming, as the principal had emailed us prior.  I didn't have a class at the time.  So I took my time getting out because I certainly did not want to be caught up in the stampede of middle schoolers, many of whom are unfortunately bigger than me.  I was on the second floor and waited to begin going down the stairs until the rush of students were on their way down.  I brought up the rear to the crowd and began walking down, again, taking my time.  

A substitute teacher who I had never seen or met before was walking down not far in front of me with his class.  He was an older gentleman, maybe 50's or 60's.  He turned around, saw me, and motioned hastily, "Come on!"

Not thinking, I first responded, "I'm coming."  And then it hit me.

"Oh... you think I'm a student, don't you?"

AWKWARD.  AWKWARD.  AWKWARD.

His eyes grew big, "Oh my gosh, I am so, so sorry."  He laughed with embarrassment.  "You just look so young.  I'm so sorry.  I'm so embarrassed."

I assured him about half a dozen times that it was okay, that it was a compliment and he needn't worry. I didn't think it best to tell him I'll be 29 this month.  Figure he thinks I must be a brand new teacher right out of college, age 22ish.

22 it is, then.