I've got no idea how to get the fact that life changes through to a guys brain... Just keep your cool... and remind him he has a family at home now... You guys aren't as mobile and foot loose and fancy free as you were 14 months ago! (9 months of no drinkin for you included!)
I will say this though... When talking to guys about important things like this... it's always best to keep your head cool and your voice level. hard as heck... but it's way more effective than getting all fired up and losing your cool!