is it normal to get attracted to my ex?

Hi am married and have a very healthy relationship with my husband. But recently after seeing my ex bf after a long time(12 years), started talking to him and feel attracted to him. Is it normal? In professional life and status my husband is far more superior to my ex bf. Should I continue having relation with my ex or no? Is it ok to cheat my husband? Coz I know that my husband would like me talking to my ex.