Watching Porn with Sister II

My brother and I are hanging out in the living room when Mom and Dad are away on a work trip. My brother insists in watching boring Sports-Pro Channel 5 so I'm watching some movies on his iPad. I found his folder titled "secret" and I'm watching the clips in awe. It's so cool to see porn stars having sex, there's a lot of enhanced boobs, huge rod-like penises, wild thrusting, golden blonde hair flipping, squirting, cumming, gooey-wetness, but is this how people have sex in real life? Do guys really have big penises like that, regular guys, I mean? I saw Dad's penis, and it was average sized, a couple times I saw my brother's penis, but he didn't know I was looking, it was flaccid, like a noodle, hanging down between his thighs before he covered it with his boxer-briefs. I know my brother has had a lot of girlfriends, he could answer some of these mysteries.
I tentatively ask him, "Robby..?"