Marriage

***Edited to let everyone who commented know.... We are getting married on August 23rd!

My boyfriend and I have been together for 4 years and we have a 5 month old baby together.

Marriage has come up in conversation a number of times, but we hardly ever go into detail about it. I've been wanting to bring up the subject, but I guess I'm not entirely sure on how to do that.

So I need some advice on how to bring it up that way we can talk more details about it.