So just got to the start of Chapter 4, and first off I'm really glad to see this continued on. There aren't enough heartwarming stories out there, so whenever a good one comes around it's always nice.
Now onto the meat of the matter, MC's next spell needs to be another spatial spell, like his pocket dimension, but able to cast on the ladies. Make 'em bigger on the inside. I mean, if he can make a spell that adjusts it so that each lady can perfectly fit him, he'll become the most famous mage ever. People would line up from the whole world over, and world peace would be reached. Everyone would want a crystal with a spell that adjusts the vagina's size perfectly to her partner.