Things between Sandra Bullock and Ryan Reynolds are heating up. In fact, the new couple have become so close that the actress is letting her 'Proposal' co-star get closer to her son, Louis.

"Sandra loves the idea of Louis having a good male role model in his life," a friend of the actress tells me, adding these two important guys in her life have already bonded. "They play together for hours, and Ryan even helps out changing the little fella's diaper."