Contrary to popular belief, the slow loris is not actually a venomous primate. Rather, the animal produces an allergen (Fel d1) from a gland in its armpit, which is transferred to the mouth when licked. When the loris then bites, this chemical doesn’t elicit a response because of toxicity; some individuals just have a strong allergic reaction. Quite astoundingly, this allergen is the same as that produced by the domestic cat. So in effect, if a slow loris is venomous, then so is the common house cat!
On a side note, can you see the small second tongue? It’s called a sublingua, and most likely functions to remove hair and debris from between the teeth - it’s basically a built in tooth pick!
Photo by David Haring (CC)
See: Krane S., (2003) “Venom” of the slow loris: sequence similarity of prosimian skin gland protein and Fel d 1 cat allergen