Blowing vape smoke in a baby’s face

It’s so hard to hold my tongue about my boyfriend’s cousin blowing vape smoke in his one year olds face. I don’t want to be out of place and tell him not to do that so I just hold my tongue. This situation is so hard to see and it’s heartbreaking that someone would blow smoke in their kids face. I also feel uncomfortable with someone call their kids cockblockers. ( I’m sure there are ways to have sex without waking up the kids) it’s like way have kids. So I’m just biting my tongue and not going to say a word. I’ll let my boyfriend’s parents handle that.

Just needed to vent about this

Edit: I’ve said something but I was told that it’s not my place or business. No one believed me about it anyway. So I’m kinda at a loss on what I can do. His kids can’t go to their mom because she threatened to shoot up the house so the kids would be in the system.