i want to initiate sex w my SO, i know it'd turn him on but i get shy and idk how. help!!!

my SO is usually the one to come on to me before sex. but recently he keeps talking about how hot it would be if i came on to him. the problem is, i get shy. idk why because once were fucking i am the opposite of shy and will do anything with him but i just don't really know what to do to initiate sex. he does get turned on kinda easily , but sometimes i try things like rubbing my booty on him etc and it dosent work , he just won't get the hint that i want to fuck every time i try. i don't know how to initiate sex in a "hot" way without it being so straight up where i'm practically saying "come fuck me" . like i said i get shy. but also don't want it to be so lowkey that he's not catching the vibe . ideas on how to "spark" sex in just the right way? tips? thanks:)