Finally, take the responsibility by law or laws of moral justice. Be honest with her and together come up with how to deal with the scenario. The National Trust welcomes naturists and has marked out nearly 1km of beach where clothing is optional. Today, Studland has probably the best known official naturist beach in Britain. Get her in her best moods, when it is the two of you, preferably, away from home. With a history going back as far as the 1920s, naturism has become a distinctive part of the landscape on the Studland peninsular. Let your wife get the information from you before someone else gives her the 'abridged' version. One of the best ways of dealing with adversity is to stay ahead of the information.
You should encourage and support her to keep that pregnancy and make sure the child is raised responsibly. A responsible man takes responsibility for his actions and that pregnancy is your responsibility. How do you go terming her as irresponsible? It is interesting how you realise this only now after sleeping with her severally. But first wait for the birth of the child then you can do a DNA test to confirm paternity then if it turns out positive you can do what will be required of you. You better inform your wife and your parents of this pregnant lady and be ready to support her and her baby because it has happened after your prolonged relationship. People already know of the story so in case she procures abortion and she dies or something happens you shall be the first culprit. I would not encourage you to ask anyone to terminate a pregnancy.