What is the father's responsibility towards his children born out of wedlock, and must he inform his Muslim fiancée about his past?

The child born of adultery is not attributed to the adulterer according to the majority of jurists. Some scholars, however, are of the opinion that if the adulterer acknowledges the child as his own, the child becomes attributed to him. This is the view preferred by Ibn Taymiyyah. According to this view, if you attribute them to yourself, then all related rights would ensue, such as the obligation of spending on them, raising them, and ensuring their religious upbringing, especially if they live in lands of disbelief and you fear trials for them. As for the view of the majority, there is no relationship between the adulterer and those born from his semen, and he is not obligated to them in any way. It is also not incumbent upon the suitor to inform his fiancée about his bad past; rather, each of them must conceal their own faults.