Ron is focused on the investigation, and that includes making sure Jamie doesn’t put himself in a compromising or dangerous position—which having sex with Daunis has done, in his estimation. It’s possible to see that Ron values Jamie’s safety over Daunis (and Jamie’s) happiness, though—and by extension, that he perhaps doesn’t value Daunis’s happiness and safety as much as one would hope. The revelation that it was Jamie’s idea to get close to Daunis, meanwhile, reminds Daunis that parts of her relationship with Jamie aren’t real. He is, as Ron notes, a federal agent working a case, not a high school student in love.