My oldest is calling my now boyfriend “daddy”

Today out of the blue while showing my grandmother a video of my oldest seeing my boyfriend for the first time in 2 months, he goes without asking him “that’s daddy!” Now, my boyfriend and I had agreed from the beginning that my son could have the choice of when he could call my boyfriend daddy or whatever he chose to call my boyfriend. I’m excited and ready,but I don’t want to push things.

What’s your other moms opinions on this?