Monkey branch theory states that she did not break up with you until she was banging some other dude. Probably that one fell through. Now you are hearing about the 2nd one.

She is telling you she has options.

IMO though, when girls tell you this, you don't negotiate or bargain with them, you keep on walking.

Problem is, when will you EVER run into an attractive girl that is legit single? Very rarely indeed.