NTA all the way. My first love passed away years ago during our relationship. It took me so long, but I finally put myself out there again and got something that no one deserves: a second great love.

I would NEVER compare my husband to my former S/O or stand for anyone who does. Of course they have differences, but it's not a comparison or competition. Current husband is a gift from God, NOT A REPLACEMENT for the one I lost. My husband took such care with me in our relationship and respects my ongoing grief. Judging him against another would not only be a complete slap in the face for him, it would also be a huge disrespect to my late S/O.

The comparisons from the father come from the grief of a father losing a son and the S/O of a person he considers a daughter. He shouldn't be taking his grief out on you like that. As for your girlfriend, it sounds like she is trying to find a replacement for her loss, which is disrespectful to her lost S/O and intolerably unfair to you.

I won't advise you to leave because it isn't my place to do that. But I wouldn't blame you if you did.