How to deal with widower boyfriend's family.?

There is something he can do about it, he's chosen not to. He can, in NO UNCERTAIN terms, tell those who are denigrating you, that you and he are an "item." And, they can either respect that or he won't be talking to them.

I was in that situation years ago. I was dating a widower whose wife died young (30's from cancer) but they didn't have kids.

In the beginning he never made me feel like I was competing with her and he really only brought her up if I asked him something. I was a good sport about it (I think) and I knew he had a life before he met me and she obviously was a very big part of it. I was a good sport to the point I helped him pick out a grave blanket for the holiday's, and flowers for her grave for her birthday and things like that. He was still close to his in-laws and I expected him to be, they went through a big loss together, her family was actually quite nice to me, I didn't have any issues with them, when they invited him to events they also included me. His family was the problem, his mom in particular, she didn't like me just for the fact that well, I wasn't her. If she hosted a dinner or anything else, I wasn't welcome because we weren't married or engaged. She would go out of her way to talk about her, how much she missed her and how nobody could be as good as her. Anything I tried was wrong to his mom, little did she know when he would go have dinner with her, it was my idea not his. In his house, he had this big piece rug in his kitchen that his mom bought for him and his wife. Well his cat took up urinating on it so it made the house smell awful so I pulled it up and put it in his basement so it could be cleaned and she was super offended and sent me (and him) a nasty email about how it wasn't my house to do that, his wife would never be that rude, etc. She was the type that was only nice to me if someone else was there and it was a fake nice, I'm not stupid. His mom was/is quite narcissistic. His dad though was always nice to me, his parents were divorced and I could see why, I would have taken up drinking too if I had to live with her.

We had other issues but his family, especially his mom was a big one. I decided it was too much for me and parted ways with them all.

Two weeks later, I met the man of my dreams. I knew my relationship with him was over so I was just seeing what or who might be out there and I wasn't even sure I wanted to date. But, I met a man who is absolutely awesome and best of all he has a great family. My in-laws are as awesome as he is, they have always made me feel welcome. He and I have been married for 10 years and built a great life and family together. Had I not walked away from that dysfunction, I might not have ever met him.

My mother recently married a man who is a widower. His son is great to my mom, but sometimes I can tell it's a little awkward for him. I would recommend seeking the kids out and letting them know you are not trying to replace their mom. You want to be there for them, but understand their hesitation. Tell them how much you care for their dad and how sad you have been seeing their father struggle with happiness with you vs the kids.

Hope this helps. Lots of luck!