How will my wife's Illegitimate non-Singaporean child stay in Singapore when we are divorcing soon

[Avian]

Hello there! Anyone knows what to do with my situation? I am a Singaporean and I am divorcing my wife(different country with Long Term Pass) but i want her illegitimate son(who is born in her country, whom i considered as my child already since the day i was told he is mine reason why we got married, eventhough i haven't adopted him yet) to stay in Singapore so he can have a good education and better life coz i know my soon to be ex-wife wont be able to do that for him. Anyone please advice me what to do?

2nd: Will the divorce affect the long term pass she has now? I'm concerned with my "son" going back to their country. Thank you in advance.

[PNGMK]

I think all you need is legal guardianship and that is good enough for a student's pass. His mother would have to consent. You probably need an agreement or similar type of document drawn up by a solicitor.