The man I'm seeing admits he will always love the mother of his child?

It had been close to 8 months since we're seeing each other. Despite all the hurt and insensitivity I experienced from him, I told him I love him & he said he loves me back. These past few days, he's been changing..more caring & loving towards me. We went out one time & I asked her 5-year-old daughter if mom, dad & her are bonding every now & then like go to the movies or something, she said no bec mommy doesn't love her dad anymorre.. I was concerned bec at that early age, she's aware what's already happening. I told her mom & dad love each other that's why she came out & the child would insist 'Nooo..they don't anymore.." she said that's what her mom keeps telling her. I got sad & opened it up with him. He got so upset. He admitted that he will always love the mother of his kid & even if she's nasty towards him(she took him to court for sole child custody & demanded to up child support she's receiving), he said he's willing to take her in again if that's what's gonna be best for their child. We're not young people, I am 36 & he's 37..the ex is 26.. I'm separated & have 4 kids who aren't living with me in the US.. Right now, it bothers me bec even tho' he said he loves me & gets jealous with my exes, he won't commit. I am in love with him 24/7 & I try the best that I could to take care of him & show him I am worth it. One time we fought he said he would never allow himself to fall in love with me bec he learned his lessons well.. that made me hurt really bad..when we got back from that last fight, he said he's sorry for all the hurt he's caused & he's been more attentive.. he said he doesn't want us fighting anymore.. He even liked it that his daughter adores me so much. Friends would say to just continue taking care of him & that someday I may get what I want- to be officially his girlfriend. But I am so scared of the ex-girlfriend bec I know he still loves her. Would I stay & wait & continue loving him or should I just let him be and move on?