I want to reiterate what everyone has already said, with a slightly different spice: him turning around and assuming “I don’t want to” is code for “I’m embarrassed about an STD,” means that he ASSUMES (rightly or wrongly) that you are too inexperienced or uncomfortable to talk about sex and he is WILLING TO TAKE ADVANTAGE OF THAT. One of the first rules of sex is “if you’re not ready to talk about it, you’re not ready to have it.”
If we start at ground zero and re-write the whole hypothetical situation into a best-case scenario: your guy has great intentions, isn’t preying on a young virgin, actually loves you and is only asking to support you for the right reasons, genuinely things you are confused or embarrassed—he would then STOP ASKING FOR SEX. He would ask if you needed to have a serious talk about sexual health, and have that conversation without any expectations. If I’m being honest, it should probably put him off a bit because he obviously knows what he wants, and if you’re not at that level then why is he in a relationship with you? Because he thinks it is okay to pressure you into something whether you know anything about it or not.
I’m not saying you’re ignorant, if it sounds that way I apologize. The fact you’re on Reddit means you have a huge head start on my generation. But if there is something you’re not sure about, there’s definitely no need to feel embarrassed. There are adults in their 20s and 30s who still don’t know much about sexual health—hell there are couples who saved themselves until marriage for religious reasons who will probably NEVER know much about it. But a caring partner will have the talk with you without any judgements. The fact that not only is he ignoring all of your attempts at communication, but is turning around and trying to ply you from another angle is disgusting. He is trying to take advantage of more ignorance than you actually have to get what he wants.
I’m really proud of you for coming into the internet for help and support before letting yourself get bulldozed. And I’m really proud of all the mature and honest answers from the other commenters. You love to see it.