in a perverted way. It was not uncommon for men to marry women much younger than they -- especially if they wanted children (my own great grandparents had a 20 year age difference between them and she was still in her teens when they married). In Wickham's case, he knew that Georgianna had money as he had grown up with the family. In the case of Lydia, she was very giddy and impressionable -- someone who could come easily under his sway and not question his actions or motives. And she was probably good company for him as well, not just sexually but as someone who didn't take much seriously and didn't, apparently, have much of a conscience.