Aside from the first Doctor clearly implying that Susan was his biological granddaughter, there's nothing on screen to show that. However, the Eighth Doctor (Paul McGann) had obvious romantic interests in many of his companions and was the first Doctor to kiss people on screen. British people used to sneer that it was non-canon and the "American Doctor Who" (the entire production was British, it was merely filmed in North America) didn't count. I thought McGann and Eric Roberts (as The Master) were better than many of their counterparts in the 2005 BBC revival.
river song