Sleeping with my ex

Ive been having sex with my ex bd for a about 6 months now. I know its wrong, he has a gf who he lives with. I cant seem to help it though, a big part of me still loves him and I always give in when he tries anything. I dont want to be this kinda person but we still have a lot of love for each other and feel comfortable together. We still talk daily and confide in each other. We have a special bond but Im feeling very bad for this and I want to stop. How can I keep myself from giving in when he tries???

I do not have him on social media but I cannot block his number as we have 2 children together. I wish that I could.

He does want to come back he asks so many times. I do not want that ☹️☹️ my trust for him would never be the same after so long apart. It feels very strange to love someone but know you can not be with them for other reasons