Ive just discovered my ex who is also the father of my 5 month old baby also has a 10 month old baby.why?

Despite being engaged to me he was also engaged to a russian woman he met 2 months before me. I fell pregnant with his child a year after we met. I have since learned during our relationship he was living with this woman in another apartment he owned!!! I never doubted where he was duriing the week as he has his own buisness and works around the country. But i cant believe he asked me out when he already had a girlfriend and agreed to have child with me when she wouldve been 5 months pregnant!!! Ive also found out that the pictures he said were his nieces and nephews are in fact his children. He decieved me right from the beginning. So he is a 37 year old man with 5 kids by 5 different women. What drives a man to do this?? It makes me feel sick he was sleeping with another women at the same time we were together. Also (and not incite racism) he is of Jamaican origin. Is this a cultural thing with Jamaican men? (We live in The Uk) I have chose to no longer be with him, but this russain women is staying with him (perhaps for money!)