Drinking&Pregnancy

Hi guys! I'm Brit! I'm 24 years old expecting my 2nd child! I have a son Graer who is almost 2. My husband and I like to entertain, drink socially, and have a good time. Whether it was at our house, friends, or out and about. Well since I'm pregnant I don't drink, sometimes I will go with him so he can but I rather be at home with our son. My husband Kory is always busy working and flying for his company. Lately he has been leaving me at home to smoke cigars and go drink with our friends. I am left home pregnant and working on my company from home. Luckily we have a full time nanny that lives with us  to help me with Graer. How do I approach him? He wasn't like this with our first child? Is he just scared of having a second baby?