I need some love advice

should i continue dating my ex while still with my current boyfriend? OK so many years i really fell for a guy that ended up leaving me for another girl Currently I'm in a new relationship its been 3years, my current boyfriend has not been a saint . . I found out a few times about him trying to see other girls. He says he changed and i really love him so we're trying to make it work Now, my ex had recently came back into my life. . He told me sorry for the past and that he really messed up. This confused me greatly because i thought we were only friends. Until we kissed. .. The feeling i get when i kiss him is a feeling i have never gotten with any1 else before. He wants to go out with me again and i want to hang out with him too I just want some outside answers on ppl who don't know me.. should i continue to date my ex or just cut him off and focus on my relationship now. Deep in my heart i want my ex back in my life because our connection is just so strong. When I'm with my boyfriend and i look at him i feel so bad fr going behind his back .. but sometimes i feel like maybe he's cheating on me even tho he loves me so sometimes i don't feel bad