Lewis Carroll wrote Alice in Wonderland in the 1860s and I'm assuming that the story takes place in that time period as well seeing as how he based the character on a little girl he knew. It's not exactly accurate to say that they didn't have divorce back then. Divorce in England became legal in the 1850s. That being said, it carried a huge social stigma in that time period and was very very rare. It's doubtful that it would be considered a plausible course of action for most married couples. It was more common for people of Alice's family standing to tolerate infidelities and unhappiness in marriage. Matches were more often made to improve social standing, make advantageous connections and profitable business arrangements than for love.

My Bad , cause I do remember that he secretly cheated on her .