1st time watchers or OG fans

I saw someone else ask about OG fans when s4 came out I have a similar question, I’m on my rewatch and just watched the headless horseman episode and phoebe sees piper with two boys. Obviously Wyatt and Chris. When did you guys figure out Chris was pipers son? Did yall catch on soon or had to wait until it was revealed. Knowing he’s her son I can see all the hints in the episodes leading up. But would love to know how yall figured it out and what yalls reactions were!! (I first watched charmed when I was like 7 so i don’t remember my reaction I just remember thinking Chris was cute hahaha)