Is it normal to still miss the relationship?

Is it normal for me to still be hung up on my ex even after he treated me like shit for the whole time we were together? is it normal that he still talks to me even when he has a girlfriend and tells me he how much he loves and misses me but isn't breaking up with his girlfriend?
We still talk and skype and hang out and he hugs me and kisses me and sends me love songs and break up songs. He apologises all the time and tells me how much he misses me ever since we broke up and how i'll always be his and that he wants to marry me one day. but he still has a girlfriend and i forget the fact that he cheated on me 2 times and treated me like complete SHIT
but i still love him? and he still loves me... what's going on? ....

note: we haven't had sex since we broke up (5 months ago) so no "he's using u for sex" comments please. I'm not easy lol he gets a lot of girls all the time so sex isn't really the issue here. its deeper than that but idk what....