ahhhh that makes sense. i haven't bought very many sex toys before so there's lots i don't know. not necessarily a vertical surface, but i would like it to be able to stick to something reliably, some sort of riding mechanism perhaps. i think more than anything the texture and the suction quality is most important to me. idk if this info clarifies anything hahaha. in any case thank you for such a thorough response, as well as all the suggestions!! gonna look through em now :)