Karnataka elections 2018: Is BJP and JD(S) looking at an underlying understanding to trump Congress?

After Prime Minister Narendra Modi praised  JD(S) chief Devegowda at a BJP rally on May 1 word spread that BJP had come at an understanding with the JD(S) in the case of a hung assembly post Karnataka elections 2018. This was further fuelled by Congress accusing the two of being in collusion. Although both JD(S) and BJP have refuted the claims, could there be any truth to it?