Things that make you doubt people's credibility

[Ebowed]

I run into this type of person all the time: married, homophobic, and points out one of every four women walking past as someone they wish to have sex with.  Also, anyone who drinks alcohol regularly and criticizes others for using drugs (the inverse of this is less common, but equally as irritating).

I also hate being around people who tell racist jokes, but that has less to do with their credibility as it does with them being a horrible person.