So my FWB Kelly says that she likes a big head for sucking....she lets it bump into her lips as she strokes out and then she swirls her tongue around it. She likes a big head for fucking because she loves nice cock in her pussy. She wants the same size head as the shaft when she takes it in her ass. She def doesn't like a fat head parting that little hole.
There seems to be a bit of confusion on what is considered to be average size cocks and large cocks. From a woman's point of view who knows what she's talking about my wife advised me that 5 to 6 inches is considered average, while 7 to 8 inches is definitely big. And anything over 8 is too big in her opinion. Girth is considered big at 1 3/4 and above. She prefers length and girth. That's all I can safely say about the subject without getting in trouble.
It largely depends on your experience and what you're used to I think. Personally I'm glad you think that one is too big and you can't handle it. I'd worry if you could.