Very generic, but Toriel and Frisk, if you want to at least consider him adopted. Goat Mom is just too thicc. I mean, i'm majority gay but mother and son stuff is a huge exception, seriously love that kinda stuff.
Annie and Hogarth Hughes from The Iron Giant movie. Closely followed by Helen and Dash Parr from The Incredibles. Both are very lovely, caring mothers with the perfect hourglass-like milf bodies. With Annie Hughes there's a plus that there's no dad in the picture.