Dating a guy who's terrible in bed

I'm dating a guy for the first time in a long time and he's such a sweetheart, he has all the ticks in all the right boxes except for sex. He knows nothing about foreplay and we have only done 2 sex positions. Is it rude for me to show him how to do things or just have a open convosation about it? I don't know. it's honestly staring to piss me off, I know that makes me sound like a bitch but I want to enjoy it! I want to cum and have some pleasure and not just have a hard dick shoved in me for a few minutes then exploded all over my stomach. What do I do ladies