Ugly Boyfriend Syndrome, also known as UBS affects all women.  Some women carry the highly virulent verion of the disease known as NUBS, or Nasty UBS, while most simply carry the dormant dna that lays in wait.  The affliction is believed to originate through nature to help mankind procreate and it is passed on from genration to generation. 

The syndrome helps guys by making even the UGLIEST guys attractive to some women.  The affected female does not even know why she finds the ugly male attractive, but she does... A woman that exhibits this behavior is known to have TUBS (Terminal UBS).

There is no known cure for UBS.  There is no known way to suppress the actived gene either.  The best thing a friend can do is to hope that the gene goes inactive on its own before children are born, in which case, she would be infected with NLBS or Nasty Looking Baby Syndrome.