Babies are seen without shirts, and almost completely without bottoms on (which means they are left running around bare-legged in their diapers all the time.) Also, when Sly is running from babyco and looking for a disguise, he ends up in a female babies stroller. He asks her to take her clothes off and she responds: "not so fast, slick. You'll have to take me to dinner first."
Very little if at all. There is some physical humour involving certain sensitive parts of the male anatomy.