Help!! My Girlfriend's Ex Keeps Showing Up After They Broke Up

A troubled Nigerian guy has narrated how his girlfriend's Ex keeps showing up after they both broke up over bad companies, smoking, long distance and unseriousness. The new boyfriend who is a member of Nairaland forum narrates the whole story here:

 Good afternoon Nairalanders, Let me start talking about how we started, I have known this lady for a long time(Just Friends) but we started talking again few months ago after about 6 years without communicating, she is the type that I really love and want to make my wife, but an issue started coming up as a threat in between us lately. To start with, she was dating a guy when we started talking again and I was out of the country then. We got along very well and things started getting serious overtime, she told me she has a boyfriend then but she doesn't really go into much details at first, when I came back, I asked about her boyfriend issue and she told me he is a cool guy but things are getting bad between them because she has been having issues with the kind of friend he keeps, their lifestyle of smoking etc and he isn't serious with any life plans which was before she found out due to long distance relationship.She ended the relationship after we met (she has always emphasize this to know how real I am about her), the problem now is that the Ex keeps resurfacing using different strategies like begging, crying and other childish act and was always like no one can take her from him, the worst that happened recently now is that the guy wanted to commit suicide, the mother and some of his family members had to call my girlfriend to please reverse her decision on the break up so that he wouldn't end his life etc. I need suggestion on how to resolve this issue once and for all. Its getting out of hand and I cant keep continuing like this, likewise herself too. All ideas, insults and suggestions are welcome.Note: She has done all her part to persuade the guy stop the lifestyle and plan toward the future and stop keeping friends that are into smoking and all those lifestyle many times before I met her to no avail, thinking she cant leave him simply because he dis-virgined her and has been the only guy she had known all of her life. I know all this details personally through a friend that attended same University with her, personal background check and her words too. No one is perfect but I don't see her as the lieing type and she open up to me on everything. Thanks"

Please drop your advice in the comment section below, thanks.