What can he say without sounding so lovey-dovey and out of character?

Well I know that this could probably go in the romance forum but I this is more of a plot hole than anything else but it can be moved accordingly. The plot of the first half of my story is heavily influenced by the romance of my two MC's. The problem is that they are about to reach a breaking point in their marriage. It involves the MMC not getting along with FMC's father. Earlier when he proposed to her, he said that he was given the OK by her father. But I never wrote the scene...

So I wonder how would a conversation between them would go. Her father doesn't like MMC because he reminds him too much of himself when he was younger (which doesn't exactly spell good news). MMC doesn't like the father because he thinks that he is arrogant, overly-protective, opinionated, and anything else he can find wrong with him. They can't seem to see eye to eye on anything but that their love for FMC. MMC isn't the most romantic person, if anything he's very blunt (which can be romantic, right? :P) and that's exactly what ticks the father off. So what is something he can say to the father without them getting into a screaming match?

And would it be bad if they form some kind of deal?

When my brother-in-law called my parents before proposing to my sister, he didn't phrase it as a question at all. This is also related to it being the twenty-first century and the fact that my sister probably would have been pissed if she'd ever found out that he'd asked Dad to "give" her to him. But my brother-in-law is from a rather conservative, religious family, so he compromised. (Dad wouldn't say what he said, but I think it was something along the lines of "I'm going to propose to your daughter, do I have your blessing?")

Your character could be just very blunt about it and lay it all out on the table. "I know you don't like me, but I really love your daughter and I'd never hurt her, and you know she loves me too and she'd be happy with me, so I'm going to propose to her and I really hope you can be supportive of us." (Maybe less confrontational. Or more, depending on the character.) If nothing else, the father would have to respect him for at least being honest.

What kind of deal are you talking about? Like a dowry, or like a "let's try not to kill each other for her sake" sort of deal?

If you're really struggling, do you need to write the scene at all? Because you could just imply that he'd asked, without showing it. And then leave it up to your readers imaginations.

@FreakierThanThou Yes I mean a deal like that. Would it be wrong or just weird?

@DarkAngel Well I did leave it up to the reader but writing the scene for myself. When they have a fallout it will give me something to go back to so that it doesn't seem like they got along and then started hating each other again.