If this is a serious problem, then my partner should leave me, because I got about twelve quilt blocks through the post from total strangers as part of a block swap, and they were themed around sexuality as well (it's appropriate for the charity the quilt will be going to). For heaven's sake, folks, it was a daft random gift swap, all very low-key. A novelty pizza cutter is not a warning sign of impending adultery. Incidentally, you don't need to make your own pizza from scratch to need a pizza cutter, they are equally useful for take-aways or frozen pizzas.
If you're this worried about jealousy, then I suggest that you sit down with your partner and have a chat about what monogamy means to you, how you feel about it, which areas make you uncomfortable, how you feel trust balances out and so forth. Maybe say you were reading an article that got you thinking, if it feels odd to be having this conversation this late in your relationship. Personally I had it with my partner a week in - I was fairly sure we were on the same page but I didn't want to be guessing this time. I turned out to be right, but that didn't stop it from being a useful conversation, particularly as a trust-building exercise. I've read some excellent articles on trust and negotiating within a relationship on polyamory websites, and even though I'm thoroughly monogamous myself, they have been useful to me as it's stuff that's important for all relationships.
If you feel that it's really about gift-giving and feeling neglected in that area, then again, sit down and chat about it. Gift-giving is an important part of human cultures, it's common for it to be something that seems as if it should be minor but is actually the site of great stress.
We're socialised to expect that a perfect relationship runs on mindreading. Of course it's total nonsense, people need to be told things about each other, and we all need to work out when we've unconsciously assumed that the other person knows something without actually telling them. Either way, work out what is really triggering this anxiety you're feeling, and then go and talk about the real issue rather than the silly gift swap. Don't go in with ultimatums, and do go in prepared to think more deeply about things you've been taking for granted.

