I have a BIL who was divorced from his 1st wife, married my SIL, 2 kids from 1st marriage age 8 and 5 girl and boy. He had joint custody; he & the X lived just a few streets apart so they shared physical custody alternating weeks. He had 3 kids with my SIL and is still married to her.
The kids were in private schools, they had the best of everything just as tho they were living full time with Dad, including their own bedrooms, and they went on every vacation and had every holiday with the BIL, and he paid for it all. Additionally, he paid the X child support AND alimony, probably over $6k a month, and NEVER complained even once.
I realize most people don’t have his income or assets, but the point is, he never shortchanged the kids or ever let them even think he resented supporting them.
That is also the case with me. And I have never bad-mouthed the ex to my son.