My (44M) ex (38F) filed for divorce earlier this year. It isn't fully settled, but we are close. We have agreed on 50/50 (alternating weeks.)

When our 5 y.o. son is with me he frequently tells me that he doesn't like his mom and that he wants to spend more time with me. I've always diverted him and reminded him that his mom loves him, but he really seems not to like her right now.

Do I (gently) tell his mom that she needs to rebuild her relationship with him or just let this lie? If I was on the other side of it, I would rather know, but I may be unusual.

Thanks in advance.