My husband LIED!

Ok so months ago he asked me if i know the Ilae's family from where i from. I said yes why? I said theyre my family from my dads side. The way he ask made me feel weird cause he never asked me the way he asked me & he was like tweaking with his fingers thats when i know something wrong & he tryanna hide something. I told him if thats like some girl or something. He said no cause a lady told him she has family & she said my last name. I said hmmmm... Thats weird a lady? Then he said one aunty babe. I said ok sure. Then tonight i just found oit thats his ex last name. I found out when she tryanna add me on INSTAGRAM. I flip put cause shes weird. She makes fake accounts saying my fiance cheating. She talks shit with my SIL. I questioned him if he talks to her he said no but i have a feeling hes lying i wanna snap cause i think he is cheating on me.

&i only knew her first name not last name.