You shouldn't use dating sites when you aren't single.
Lou is looking around at different sites on the computer when his wife wasn't home.
Lou wanted to find someone to chat with.
Lou goes to a sports forum and joins it so can talk with fellow sports enthusiasts.
Lou goes to a dating site and creates a profile, so he can message people.
Lou makes a new friend who is as passionate about sports as him.
Lou gets into a fight with his wife when she sees the dating site on the computer.