1. I went to a leather and chains exhibition last week.

2a. Took you long enough to get here! (to someone familiar and good-natured enough not to be affronted by this, since it's not polite, or you don't care if they are affronted and you're ready to duck when they swing)
2b. Goodness, what held you up? (more polite)
2c. [Grandma, Auntie, Boss], did your [leg, cab driver, some other factor] hold you up? (about as polite as you can get -- there really is no polite way to reprove someone for mere tardiness)