There was a running joke throughout Guardians of the Galaxy Vol. 2 that Drax has sensitive nipples. This is initially brought up in the opening credits scene when the Guardians are waiting for the interdimensional beast.
Gamora: Drax, why aren’t you wearing one of Rocket’s aero-rigs?
Drax: It hurts.
Gamora: Hurts?
Drax: (muttering) I have sensitive nipples.
Guardians of the Galaxy Vol. 2
It's brought up again when they are fighting Ego and Peter puts an aero-rig onto Drax.
Quill: Someone needs to be up top when Kraglin arrives. Drax, take Mantis.
Drax nods. He picks up Mantis. Quill grabs the aero-rig off himself and slaps it on Drax’s back, which automatically wraps around his upper body.
Drax: Ahhh! My nipples!
ibid
However, when taking a closer look at Drax I can't see any nipples on him. In fact even when comparing the character to the actor I am struggling to see Dave's actual nipples underneath all the make up.
So, where are Drax's nipples?