A friend of mine was falsely accused for sexual harassment because of this and was fired from Wal-Mart once as he decided to gotten into a romantic relationship with his co worker. This is a rule of thumb that I would never agree to when it comes to the workplace environment and police was contacted to be involved in his case. He suffered from depression from this and I called him up to counsel the guy and thankfully from this accusation, he was thankfully and gracefully let off the hook. And another worst case scenario when it comes to dating your fellow co worker is breaking up on bad terms and both of you had to be assigned to work together the next following day. It's an awkward situation to be in and would risk the company.