Should I Forgive My Fiancé For Refusing To Tell A Lady Off Because Of Me?

Hi Ladun,

                 

I'm in serious pain and so confused right now. I really need advice on this issue I'm having in my relationship. I've been dating my fiancé since 2yrs now and he proposed to me in May. There's been ups and ‎down but we manage each other and we are happy.

 But there's this girl lately that I'm not finding her friendship with my fiancé comfortable anymore. He said she is his friend's ex but their closeness lately has been giving me concern. She flirts with him not minding my presence.