When you want to take a Man’s Cock up your ass you need to accept the fact that sometimes it’s gonna hurt. Really hurt. Especially if he’s hung and fucks your ass like a brutal barbarian (which is his every right).
At such times you simply Power Though. No other options for a true slut.
Remind yourself of the end-goal that will make it all worthwhile: His Thick Load pumped into your guts.
And if you don’t think you have what it takes to power through the pain, then tell the Top beforehand and beg him to MAKE you power through. No matter what you say, no matter how much you beg him to stop, let him know he is authorized to keep going unto HE’s done.
That way, His power will power you through.