My dick is about 6 3/4 to 7/8" long and I will often enter that 'second hole', aka bend, but only if I take a slow and gentle approach with a willing and trusting partner. The payoff for me is the feeling that I am entering through another tight 'anus' with a different texture on the other side. You NEVER want to pound your way towards it, and I've never try to pound even after I've entered it. In the right position (I found it easier to get to when the bottom is in my sling), the entire head of my cock will be past that point and it feels exquisite. Just gently rocking my dick in and out of that hole/bend is enough to get me to cum with incredible sensitivity. Bottoms seem to really enjoy it once they are eased into me penetrating it. I've been told that it feels like they are totally opening themselves up to me in a way that they've never (or rarely) let other tops go.