no you talk to her and tell her how you feel don't flirt with others girls hun im sorry but if you want her back you need to be the man you are and tell her how you feel its that easy she will be so happy you came back or was even thinking of her lifes to short and you should tell her how you feel
From experience acting like you don't care is not a good idea. Me and and a girl I loved broke up and I tried the whole not caring thing and it didn't work. In fact we didn't talk at all for 2 months. Just about 2 weeks ago I broke down and called her. A week after that I got her back. Talk to her and let her know how you feel. That's the best way in my opinion.
You gotta be careful about the off And on thing. But if she's single just let her know you still like her and want at least one more chance. If she isn't.. Well... Umm.. Wait till they break up. Just try not to b the reason they break up and she'll get mad for your lying and what not..