LOL. I love how you just carried on and you both ignored it I would probably have done the exact same thing!

One of my old co-workers accidently did this in email form. She was writing an email to the sternest, least warm, and most intimidating of our bosses, and at the end, instead of just signing her name, she accidently signed it "Love, Diana". Oops! He never commented on it and neither did she.