I still have small feelings for an ex?

don't know why, but after everything ive gone through with my ex, i still have small feelings deep inside, like no matter how much hes hurt me i could always go back to him or forgive him, The other day he text-ed me and we got talking and he said are we mates again and i said yeah and i don't no if i still have feelings for him or what even though i go out with a really nice lad.