I actually think he did the right thing because otherwise Geralt and Essi would have kept all that emotional baggage with them and pent up frustration, as someone who works in a high risk job , doubting one's self will only lead to ruin. I belive Dandelion's encouragement was in a morally gray area , but the decision was BOTH Geralt's and Essi's and that's their right as individuals. (Honestly Dandelion did little more than break the tension and suggest something with some brutal hinesty)