Need to learn to bottom more effectively ...? [25M][NYC] (xpost - bigdickproblems)

(x-posted - I'm sure this is a REALLY COMMON question here but it's my first time posting, so... yeah)

[NSFW] So, I love big dicks. That's a given. But I've noticed that when they're TOO LONG (9in+), they hit a part inside me that I think should feel good but is actually really painful. Like kind of a stabbing pain that leaves me running for the hills, lol. It usually happens when he's pounding me out after I'm opened nice and wide and even though I should be loving it, I tend to want to get it over with as fast as possible when I start having pain. I usually tap out after 10-20 mins and I DEFINITELY cannot take anymore cock once I've cum. I've heard some stories about the "second hole" (??) and getting around curvature in the anus and stuff but every time he hits that spot I want to stop or inch forward because I'm just afraid of injury or something. There was ONE time I had a really talented thick BBC top who didn't make me feel pain at all, just immense pleasure, and I even came without touching myself at all (a first that I would like to experience again as much as possible) but I have no idea what we did that was different. I want to train to take bigger cocks - hopefully some of you boys can assist. Gaybros, help??

Bonus pic: http://imgur.com/WxPS7NL