My BF is embarrassed...

My boyfriend has been pretty successful and has been the financial support for a lot of his family members. They look up to him and expect him to have the best of everything and be able to give them money all the time. We put our money Rogetogether and do everything as a team. We agreed on a budget because we are trying to save and buy a house so we're being frugal with spending. But he secretly gives to his family without discussing it with me sometimes. He just tells me after doing it. His sister had a baby shower and we agreed to buy her a gift that cost $200. He later told me he also gave her a card with an extra $300 that we didn't discuss and agree on. I felt that was a lot to give. Plus, his sister isn't hurting financially. But he felt that a $200 gift was going to look cheap coming from him.

Now we're in town with his family for the holiday and I reserved a room at a motel 6 to save money. His uncle wants to hang out with him tonight and he said he was embarrassed to invite him to a motel 6. He was ok with this being that during the holidays it was hard to find vacancies until he was pressured to spend time with his uncle. So he sent me to the room while he stayed at his family's house but said he's coming after spending time with his mom. But when i called I got the feeling that he wasn't going to come. He said he really didn't want to get together because he can't spend and treat his uncle to a nice time like he would usually but that his sister is really getting on his case saying that he needed to spend time with his uncle before everyone left town so he feels obligated. His niece always asks for things like Jordan's, clothes, to be taken out to eat at expensive places etc and told him I'm not as nice as other girls he's dated in the past. He said he'd talk to his niece but At first thought it all made me feel offended. I'm frustrated with his pride and feel it's childish. I feel like everyone should understand that we're trying to get a home and budgeting is important and being frugal doesn't have to look bad. I hate that he's embarrassed by what I think is our mature decisions on spending. But I feel like his family thinks I should have no say in him continuing to do what he always has. Although he agrees with me he seems very down whenever he has to say he doesn't have it to spare. It really affects his mood and I don't think we're able to enjoy our time together when it's on his mind...

Should I let it go and just tell him to hang out with his uncle at his mom's? Am I wrong to think his down mood is childish?? His giving to his family has delayed us getting the home we want a few times...