Best friend & FWB

I have been best friends with a guy for about 6 years. I’ve known him for 16 years. Over the last 4.5 years we’ve been sleeping together. In the beginning we kinda did our own thing but over the last 2 years we’ve only slept with each other. This man is legit my best friend. We are extremely close, our kids are close, we are parent figures to each others kids, he sold his house to fight for full custody of his kids (couldn’t afford his mortgage and his lawyer) so he lives with his parents now who are my neighbors. He stays with me every single night his kids are with their mom, we do dinner together after he puts his kids to bed when he does have them and dinner after he works the nights he’s kid free, we spend every moment together that we have free. He has been there for so much as have I for him. About 9 months ago he started talking to some female who lived in another country. I saw the messages and it was just typical chatting. Eventually i saw things like “baby” from her and said something. He would just ignore me and tell me it’s because she’s not from around here which i didn’t believe but left it alone. She traveled here about a 1.5 months ago and visited for 2 weeks. Now said female claims she wants to move here to start a relationship with him. This has caused the biggest fights between us. Like massive. I threw his stuff out of my house at one point because of an argument about her and told him he cannot sit there and tell this woman he has feelings for her while he’s cuddling me every night, having sex with me, being in my house every moment he gets, taking me out, having me cook for him, do his laundry and clean up after him, do pick up and drop offs of his kids when he’s working, spend time with my child, etc. I am 100% aware we are not “dating”. I have wanted for so long to be something but have never pushed it with him because of his past (2 women cheated on him and he has constant battles with them for custody of his kids who he now has 80% of the time). The other morning we ended up discussing this female as calmly as we could because it always blows up and he did admit to me that he has feelings for her but truly he doesn’t think she would uproot her life to move here. I told him that he doesn’t understand how much this hurts when he knows how strong my feelings are for him. I ended up getting out of bed to go cry in the other room. I came back after gathering myself and he pulls me close to him in a spoon like position and holds me so tight telling me that I am his best friend and he will never let anyone come between us. So again I tell him if he has feelings for this woman he cannot do these things he’s been doing for the last 2 years. I asked him if he loved her to which he says “I have feelings for her”. I try to pull away from him and he rolls me over. He attempts to say something but won’t just say it. He tells me never mind because this will just cause an issue. I demand he tell me whatever he had to say. Eventually he says “I love you but it’s just not the same way you supposedly love me”. Sooo here I am a few days later not knowing what the hell to do with my life. Do I just hush about the woman, hope she goes away, and hope for the best? Do I cut him out completely (we both have kids who are involved and we spend time all together regularly so this hurts them too)? It’s impossible to sit here and maintain the same situation that we’ve had and not have feelings. Advice and input please. I’m really struggling with this.