Am I wrong?

So my bf and I are about 3 weeks from having our first child. He has these family members who are always asking for things from him. They ask for money, cigarettes, etc on a daily basis. He has this cousin and her husband who both work, yet somehow all their money is gone one day after payday. I don't know where it goes because they don't have any bills, they mooch off other family members and couch surf from one place to another, never paying rent or utilities anywhere they stay. So literally all they have to pay for are their phones and then diapers/formula for their kid (oh, and cigarettes because they go through two packs a day). I'm so sick of them asking us for money. The husband has now started bumming cigarettes off my bf everyday at work. He's literally bumming at least half a pack or more everyday, but my bf just will not say no to him. My bf "feels bad" for them so he always gives in. Well now they have resorted to asking for diapers. They know we got a lot of diapers from our baby showers and are now asking for those as well because magically all their money is gone for the week and the baby needs diapers. I'm so sick of this shit. My baby hasn't even been born yet and they are already asking for us to share his stuff. My bf can't say no to them, so he just didn't respond when they asked. I'm furious. We are struggling on our two incomes to make ends meet, we can't support two more grown ass adults who make poor decisions! Am I wrong for being pissed? What would you do to make them back off and quit trying to mooch off us?