I'm horrible at riding 😒 tips? Lol

I love riding my boyfriend for the first 5 minutes I'm like oh this feels good and then I get tired like fuck this shit my legs hurt lol I really wanna last longer but I can't I get so sore on my legs an that hopping up and down shit is like a workout I tend to give up and it sucks cause he's tired of doing all the work or he will be like damn babe can't you last longer? I get sore 😂