Bro Daihai,
since the mistake was made and not much you can do but damage control. If I were you and wanna to keep the LB 1 I would express the desire of keep her as the ONLY love one. Spend a lot time with her and may be accidentally show her another interested party that you just rejected and ignored. Faked text messages and emails can be leaked for her to find out.
I have my share of info leaks out as I deleted my (KTV girls,XXX) photos in my computer - I delete all history when I heading home on all my cells from China and my daughter went through my garbage can and retrieve them for my wife to see. SHIT SHIT... Now I went through the folder once in a while to really clean off all traces.
One thing to remind everyone is that the deleted emails from your mail box actually went into trash box only and you need to erase them through the trash can or garbage can in your window. Some real software expert still can trace back the deleted mails in your harddrive but most MM are not that sophicated in computer skill. If they are, then you are in the wrong place and should stay home or don't use computer ar all.