For some reason, a LOT of tops think they can just ram their cock into a bottom guy, and start pounding away, no lube or anything.
I learned that I had to take charge of the situation, provide the lube, offer it to the top guy, and actually tell him to take it easy, going in.
One wonderful exception was a time that I posted an ad on CL, saying that I wanted to get together with a top, to party, and that I didn't get fucked. Looking back on it, I'm surprised that I received any replies. LOL. The guy I hooked up with should teach tops how to fuck, he was that good. Of course, partying definitely gets your hole more in the mood, pretty quickly, but this guy really took his time, used Gun Oil (sp?) lube, and was in me before I knew what was happening. We ended up with him fucking me in just about every position imaginable.