My father-in-law doesn't respect me as a man no matter what I do

Photo byJD MasononUnsplash

My wife (28F) Emma and I married 3 years ago and have 2 babies (4F & 3M) however we've known each other since we were 16 because our younger brothers (both 23) met at a math program and became best friends.

My dad is a bodybuilder and so, my brother and I've always been close to him in that aspect, lifting, running and training with him, we are in good shape and thanks to him my brother and I have pretty good bodies, I mention this because apparently is the only reason my FIL doesn't seem to accept me.

Emma and I began to date in my senior year of high school, she's a smart, loving and caring girl, she's also very beautiful in every aspect I can think of, and is dream came true to me. Ever since she introduced me to their family my FIL took a dislike in me, at first he said that he didn't trust me, that I was young and a player boy who was soon to go to university and ''he knew'' how men like me were, that I'll probably cheat on Emma or hurt her heart with all the attention I seemed to like. He never thought that we'd last this longer and openly gave me ''a year or so'' to leave his daughter because I was probably that kind of guy. Emma used to fight him a lot in this, always defending me and telling him to stay out of our business because she loved me, trusted me and that this act of macho dad didn't fit him.

Every visit to her house was awful, her brother and mom liked me very much and were kind to me, but her dad always tried to test me by making me do work around the house with him and laughed me when I didn't know what to do, asked me about things he considered ''acceptable'' for a man, challenged to do hard work against some of his friends and straight out called me ''pretty boy'' in front of everyone just because of my body. I never considered leaving Emma, but I did eventually ask her to let me pass from her family gathering unless it was really necessary for me to attend and she said yes. But when she got pregnant with our baby her dad turned this disliking into disapproval, he said that I ruined her daughter's life because I couldn't keep my stuff in my pants and demanded that I marry her in the spot, I guess that was it for Emma and she kicked him out of the room and cut him off for about 8-9 months until he came back on his knees apologizing to her.

I've tried so hard during all these years to have a proper relationship with him, I've proved that Emma is not someone temporary and that I'm 100% committed to her but he doesn't seem to care, for him I'm still the 17 year old his daughter brought to the house. She has told me to let go, that she doesn't care what her dad thinks of me because she adores me but I don't know, I guess I just want him to like me for her and our kids, but I don't know how and I need help, should I approach this in a different way or just let it go?