PG-13Tobias and Tris don't exactly get hot and heavy with each other. More like… warm and light. It's all very over-the-clothes and fairly tame, and although Tris says "I feel warm everywhere" (3...
There isn't a single literary, philosophical, or pop culture allusion in Insurgent. All the characters are shut off from the outside world (if it even still exists) and are ignorant about the likes...