I think I'd schedule a neuter for the three year old pronto! He's probably getting aggitated with all the hormones coursing through his body being springtime. This should probably solve the problems quickly. I'd keep the 3 year old separated for several days after surgery as anesthesia can cause them to smell foreign to other cats. Good luck. Low cost available through Friends of Animals 1-800-321-PETS and ask for a list of vets in your area.