I only let anyone to cum in my ass if he can continue fucking after he cum, then it feels really good. Otherwise i will want him to shoot in my mouth and will swallow
When i know that im gonna get fucked, i clean my self real good, i wash my ass inside, and maybe i can suck him during and after to make him cum. But if it wasn’t planned, then its a different story, in that case i will give him a nice long blow job before i give him my ass