Do you mean that you want a numbing lube because you want to avoid pain? Being numb for sexual activity is actually problematic, as pain is your body's way of telling you that something's not right, and it's not unheard of for internal tearing to indirectly result from the use of numbing products. If there's no pain, there's no way to tell that things might be getting a little too rough.
It's best to work your way up to whatever activities you have in mind that might make you want to use a numbing lube. Relaxing, being fully aroused, and generous use of (normal) lubricants are key. Really, sexytimes shouldn't ever feel painful (unless of course you're into that).
Besides, why would you want to feel less
when having sex? Seems counter-intuitive to me.