I need help

Emily • Mommy to the sweetest little princess ever* baby number two on the way!!

Okay my boyfriend and children's father is 22 years older than me we have a 16 months old and a baby due in January (I'm turning 21 in December by the way and he's 42)we've been dating for two years now and we live together. My question is when should I ask him about our future as husband and wife do you think that its possible or that people will have problems with the idea? I just don't want the times I have spent with him and the struggles we have been through to go to waste I want to be sure about my future with him.