Somehow I strongly feel that both Vrinda and RB manipulated so much.... Rb was well aware of Vrinda's feelings for Yug, still he adopted such a way that at the end Vrinda broke down and resolved to go for RB.
Secondly, regarding Vrinda as soon as she decided for RB, she and RB made sure that yug does not come in their way. RB made Vrinda talk to Yug about marriage as he was pretty sure Yug would never say no to Vrinda. Thus RB knows very well that Yug still loves Vrinda and he just wanted to get rid of Yug from Vrinda's life. This was manipulation to the highest level.