Is texting ur ex while in a relationship cheating?

??

Edit....okay so me and boyfriend are together for 7 months but me and my "ex"(situationship) is just a very emsse duo story but idk lately mu feeling idk they are messed up and my ex followed me 3 days ago and in 2 days it's his birthday an dim think I should want him happy birthday but I dont want to hurt my boyfriend bc he is a very good guy