Unconfrontational fiance

My fiance is extremely shy, quiet and confrontation. Including to his mother. How me and his mother got into it was I made a Facebook post that she thought was directed towards her and made another post about it without saying my name. So I screenshoted her post and posted it on my Facebook and said "Next time tag me Kelly☺." So then we went at it in the comments. We all also go to the same church so it's been awkward at church and they had a cook out to celebrate pride month(we go to a very accepting church) and his sister brought up our Facebook beef. I told her I would drop it. Kelly just needs to keep her name out of her fucking mouth." She told my fiance "Are you gonna let her talk to me like that " Then I asked him "Will you let her talk to me that way?" And he just shrunk in his seat. He didn't defend me at all so me and his mama got into at that church and they said if we control ourselves we have to leave. Me and his mom then got into it with the pastor and had to leave. My fiance said nothing. Who is right and who should be be defending?