I'll tell you why: In the head of a man, they've 'traded up.' They found another woman more useful than you. Women aren't the only ones that can be golddiggers. Thank God it ended when it did or you'd be the one being used.
"I love you." Rose Tyler... "This is me getting out." Martha Jones... "I don't want to go back!" Donna Noble... "Raggedy man...Goodbye!" Amelia Pond... "Don't you dare!"... "Let me be brave..." Clara OSWIN Oswald