Well, for one thing, you're going to need to have a conversation with him outside of the bedroom about this bad habit of laughing at you in the bedroom. You're also going to need to have a long conversation outside of the bedroom about why he's feeling awkward, thoroughly enough that it's cleared up and he ceases to stop sex due to feeling awkward.

I kind of suspect it's because he was taught never to 'mistreat' girls from a strict Christian household and he is too afraid of hurting me to give me what I want.

Have you talked to him about how you're not made out of glass and spanking you on the ass is not going to cause you to break and shatter into a thousand pieces?

without him slapping me in the face with his dick?

Well, it sounds like the dude has a very literal or even legalistic mind when it comes to this kind of thing what with him robotically doing what you told him and only that, so you're probably going to have to formally draw up some rules.

So it'd be fairly easy to make it clear that turkeyslapping you is a hard boundary and thus verboten.