I don't know how to face her

Good day house, please I need your help on how to handle this. My friend and I have been really close since university days and she has been nothing but nice to me, when I lost my job, she stood by me and offered me accommodation when I couldn't pay my rent, it was during this period that I started developing feelings for her husband. I moved out of her house 2 years ago after I got a new job and it wasn't until last year that her husband and I started seeing each other and dating. I am presently pregnant for him and he has offered to marry me because he is Muslim and his religion allows him to marry multiple wives. I feel like a bad friend but I have to marry him because I am already 5 months gone so it is hard to ab.rt my baby. The problem I have however is that I lied to my friend about the father of my child, I don't know how to face her, please help me.