3 crazy ideas.
1. A way to level up tentacles. Think of a locker with tentacles with mouths or tentacles that either do oviposition or knot lock.
2. Aphrodisiac breath. If a girl walks through a cloud of Aphrodisiac breath she will go into the next locker available. If it is an infected locker you will have a limited time to use the tentacle. If it isn't you can infect the locker while she is in there. If you level up that ability you can read her mind and take advantage of her kink.
3. Icons on leveled up lockers that tell what kind of kinks are inside. Match the kink to the right locker for extra points.