i think your dad is probably a little put out that you want to share the moment with your step dad - but being that it is YOUR day and you obviously have a lot of time for your step dad, i think your dad will just have to accept it

you don't need to "bring it up" again - you have asked once, and it's out there - you can't have your day held to ransom over your dad's response - make your arrangements with your step dad and then go back and say "ok, this is what is happening" - if he respects you as his daughter, he'll fall in with your plans (even if he whinges a little in the process!)

it's damn hard to make everyone happy all of the time - and this is one of those occassions where it isn't about making THEM happy - it's about making YOU and your partner happy - and THEY should be bending over backwards to make it a perfect day for you

congratulations on your engagement hun - hope your wedding comes together to be the perfet day that you've been dreaming of