The reappearance of San at Tharn's birthday party and his presence afterwards creates jealousy from Type.  That jealousy only grows after San makes a point to tell Type that he was Tharn's first "partner".  

After Tar bumps into Tharn unexpectedly, Tar begs Tharn for a second chance at their relationship.  Tar's persistence weighs on Tharn and is noticed by Type who is also learning more about Tharn's past from Lhong.