Why do guys put 69 in their dating profile usernames?

I've been trying online dating for a while with little success. One thing I've noticed is guys who try to come off decent in their profile descriptions but have a 69 in their username. I'm sorry this just sends a pervy message to the women on the sites. Is that the imagine men really want to portray of themselves?
Why do guys put 69 in their dating profile usernames?
Post Opinion