It's a dream scenario for his parents, Andy and Kerry.
"He is great with him," Kerry says. "He's gentle. He loves to touch, hold, and feed the baby. He helps with the diapers."
The last line gets Dylan excited, who has taken a special liking to helping his parents around the house.
"I help Daddy and I give Daddy the wipes!" he shouts excitedly.
Of course, part of being the older sibling when a new baby comes around, is all that attention Mom and Dad gave Dylan for the first three years, is now getting split into two people.
Even with all the preparation in the world, it's hard to convince a toddler to not be even a little jealous.
"He'll act out if he's not getting attention," Andy says of Dylan. "We knew he knew it was coming, but he didn't realize [Cole] was going to be a 24/7 deal."
Learning how to become a big sibling is a dynamic Aimee Fleischman deals with every day. As a parent educator with Wellspan Health, Aimee teaches "Super Sibling" classes where kids of all ages learn how to deal with the trials and tribulations of having a little brother or little sister come into their lives; from the lack of attention, to learning how to share more.
Aimee also teaches parents how to handle issues like jealousy, and the best ways they can interact with their oldest child so he or she knows they're not forgotten.
"It's a huge transition," Aimee said. "Kids are resilient but they have big feelings too. So it's best to be patient with them, and remember to take time to have one-on-one time to make them feel special."
Andy and Kerry Rose are learning every day how to navigate parenthood for two young boys.
In Dylan's case, Kerry says when it's time for personal interaction, the focus is always on Dylan, and rarely little Cole.
"A lot of our focus is what we're able to provide for [Dylan] and not the baby," she said. For example, I won't leave and say, 'I have to go take care of the baby.' We try to take the focus off of [Cole] and that has helped Dylan realize it's about us, not just the baby."
Sibling classes are available at all major regional health networks.