>>399287
first tip i can give you is practice, but even then that doesnt always work.
theres a few things you can try though,
there are lubes that are specifically made with a numbing agent for anal, so you can feel numb the sensation a bit while you're building up, the lube will eventually wear off and you'll go back to normal.
You can try edging, like getting right on the edge and asking your partner to slow down and just take it easy while you calm yourself down.
and finally, id say that just own it, cumming fast especially for a bottom isnt a bad thing, As a Top myself, i see it as a huge compliment that im doing a good job. So maybe your partner feels the same.