In an effort to amuse (or sometimes annoy), you took a joking approach to conversations 10 times across your career.
The option is under Suave stance. Bear in mind that this choice will lose you Reputation or make you miss out on chances for +Reputation with some characters; where relevant, alternatives will be pointed out.
Locations where option is available:
6. First node at start of Find Nasri the Arms Dealer (-1 Reputation with Yancy if alarm is triggered; +1 Reputation if alarm is NOT triggered)
7. Fifth node (Sixth if you extorted or executed Nasri; add one more node if you chose "Interrogate" earlier on in Shaheed conversation) after defeating Shaheed in Intercept Shaheed and Recover Missiles 8. First node in conversation with Albatross at safehouse after Assault Lazo's Yacht and Retrieve Data if Sis was spared (-1 Reputation; "Practical" instead will give +1)