For mummies with more than 1 kid, how do you divide your time between them? Do you feel guilty towards the other when you are playing with one? Almost 5 months passed & I'm still feeling the same!

I'm a SAHM with a 3.5yo and 4.5mo.. My elder one goes to 2 hrs kindergarten so eventually I'm still with the both of them most of the time.. Even so, because I'm exclusively breastfeeding my younger one, I still find myself stucked with the younger one and the older one need to play independently most of the time.. So what I like to do is to bring them out where my younger one can sleep better n I can focus on doing things together.. I also discussed with my hub that I'll date my older one out for a few hours or a day once in a while to bring him for movie, play, meals etc while my hub will take care of my younger one at home.. Its possible since I'm still pumping bm once a day so hub can feed him while i'm away..