Boyfriend likes using food

If you said no to the marrow and he still uses one thats rape.
You did not consent to that nor did he accept no for an answer.
If I were you I would dump this freak as he has no respect for you and that will only get worse over time. Doesn't matter how lovely he acts otherwise. Lots of men put on the old fashioned gentleman-thing to rope you in. Trust your gut and don't let him pressure you into anything.

It's Not normal if he does it and you don't want it. I don't think it's normal anyway. I think he watched too much of the weirder porn, but if you were into it I'd say go for it, but it seems like you're Not cool with it and that means the boundary is either we don't do that anymore or we go our own ways

He probably meant by surprise you you wont know it was the marrow until afterwards. As in it wont hurt and you'll be surprised he did it. Since he likes to make you guess what it is.

Don't be afraid to dump him if he violates you with something despite you're not wanting it! If he ever disregards your no then that's rape, and rapists don't deserve love, or companionship!

It all sounds normal except when you said no and he said he’d do it anyway, when you were tied up. You need to work out a “safe word” that really means no, and use it when you’re uncomfortable. He need to agree to a safe word.

My guy likes to shove random objects in me too. One thing in particular was super painful and he listened and slowest took it out. Y’all need a safety word or something if he’s doing things you haven’t done before while you’re tied up and helpless.

Obviously, inserting objects in the vagina creates the risk of abrasions and tears. Whenever anything is inserted in the vagina, there's also the risk of introducing random bacteria and viruses to a warm, damp environment.

Putting foodstuffs in the vagina can seriously screw up the natural pH, and that can in turn result in an upset in the natural balance of healthy and less healthy microorganisms there. The women I've known who have had yeast infections didn't find them enjoyable at all.

As for whether his interest in this is "normal", that's a very good question. I can assure you he's not the first man in the history of our species to get off on stuff like this. If you can bring yourself to, do a search for "extreme insertions" on a porn website, I'm sure you'll get loads of hits. It seems to me that the most important thing is how much you trust this guy. You also need to ask yourself how confident you are that he has a good enough understanding of your anatomy and enough self-control that there's no risk of him getting carried away and shoving something rigid up you so far that it causes internal damage. And, yeah, women do give birth to babies, so the vagina is obviously capable of stretching quite a bit, but that doesn't mean that the stretchee actually finds that enjoyable.

And if he doesn't give a shit about that, then you should be seriously reconsidering this relationship.

Food can be fun.
Main concern would be infection or lost item.
Emergency rooms see numerous people every month for problems where some one was using an object and it broke or left part of it inserted vaginally or in the rectum.
Play carefully but also remember partners like to continue to experiment, it's food right now, what's next? Objects, other people. If he does the marrow with out your permission then being tied and blindfolded could be concerning.