How should I handle my boyfriend’s family?

So my boyfriends family is starting to get under my skin. All I have ever done is been nice to these people and the lack of manners they have are rude. I said happy birthday and gave his sister a birthday present and she doesn’t have the respect to say thank you. Other people said happy birthday in front of me to her and she said thank you and when I said it she said nothing. I commented on her Instagram picture she posted yesterday and liked it and said she’s pretty and she didn’t answer me but answered everyone else’s comment. I sent his mother a photo collage that cost me $50 and she couldn’t say thank you. The mother sent me gifts a few days ago and I said thank you. I just don’t understand why his family is lacking manners towards me and it’s really bothering me and I’m not sure what to do about it.
How should I handle my boyfriend’s family?
Add Opinion