He’s being such an ass!

Hey everyone, I need some advice. My boyfriend and I have a son who is soon to be three. Lately our son has been crying and whining over pretty much anything while testing/pushing our buttons. It’s been frustrating to say the least. However, while I know that his behavior comes with the territory of the phase we’re in, I’m not sure my boyfriend does because of how he can treat our son when he enters these less than ideal situations. For example while I was making dinner our son woke up from a nap crying (again about who knows what) and instead of correcting the behavior, he began yelling at him and calling him a crybaby. So when I heard this I jumped in and asked him what his problem was. He said he was tired of our two year old acting like a baby and crying over everything. I told him that’s how all two year olds act and that it’s our job to effectively correct the behavior or allow him to have his big emotions when he is being a fussy toddler. He then replied saying he needs to figure that s**t out while proceeding to ignore any forms of communication our now calm child was trying to make towards him. I am just at a loss of what to do. There are times where I feel he expects our son to behave and think like an older child and I just don’t know how to get him to understand that this is normal behavior for a toddler. But what’s not normal is him getting mad or shutting down because of crying. Any advice?