DK is the true male combination of the 70s sad/old ma + evil mother-in-law who were experts in playing mind games and possessively hovered over their sons with mad jealousy.
Don't know why Savita left DK, but his crazy insecure clinginess would be reason enough for anyone. Still not sure why she didn't maintain relations with her son though...I guess there are bigger skeletons in DK's closet which will emerge later.