Communication issues between men and women are notoriously difficult. There are about a thousand books written on this subject. Sorry this problem plagues you and your coparent.
Now, are you two together? I couldn't tell from the way you worded your post.
My husband, thankfully, has always deferred to me in the area of raising our kids. BUT, I have to be careful. He wants to feel important too. So, I have to make sure that I really take into account what he says. My husband would take my kids on these 'walks" and they would come back filthy and holding rocks with at least two scrapes or bruises on each kid . . . and I was like "NOOOOOOOOOOOOOO" inside but I just smiled and said "glad you are spending time with the kids honey". And you know . . . in retrospect, a few dirty kids and loads of laundry didn't matter as they STILL love these walks and are rough and tumble boys just as they probably should be. I grew up with sisters and kids getting dirty and cuts and scrapes while exploring wasn't our norm. . . . but I'm raising boys! So, his 'different way' is fine.
Don't know if I am making any sense.
Anyway, I'm trying to figure out exactly what is happening between the two of you. Is he correcting your parenting or something like that??
I try and whenever i do im told im being negative.
You can't keep your feelings bottled up because the feelings will only build up till your ready to have that explosive moment which will make things work. So what I suggest is that you and him start on open line of communication especially if y'all will continue to co-parent together. Now I will say this does not gareentee he will not still sweep things under the rug but at least he will know how you feel and might start to take your feelings in consideration.