Will she learn to trust me if I keep talking to her?

You dated B a year ago, for 2 years. Had an awesome relationship with her, though some things could have been better. You met K in college. Hit it off as friends, even flirting sometimes. Smokin hot. You cheat on then leave B for K. A couple months into it, you leave K because you can't stop thinking about your life with B and how put together it was. You then realize you made the wrong decision so you do everything in your power to get K back in your life, and you do, but she has lost a lot of trust for you and tells you you need to work on fixing this. Agreed. Although B lives a lot closer to you, you make sacrifices like not goin to places when you know she goes. 5 months go by and everythin is raet with you and K :) You run into B at the store and make small talk. She texts a few days later needing someone to talk to about how she lost her best friend. You know she doesn't have anyone else so you listen. You can tell she isn't over you. You keep this from K, but she finds out. It worries her. You are in love with K and wouldn't go back to B, just being there for her. K says she can't continue to be your girlfriend if you keep talking to B more than necessary. (She says weekly is just too much) It's putting an obvious strain on yours and Ks relationship. Do you stop talking to B or tell K she needs to get over what happened and trust you again. She finds it difficult because you didn't come out and tell her you were talking to B again. Damn. Would you even trust yourself? lol Sooo to talk to B since she has no one.. and try and show K everything will be fine and try to fix our trust issue while still talking to B, or just let K walk away...?