Is it normal that men with really large penises have trouble getting fully hard

Had dorm mate that lived next door that had very large penis, almost comically so. I'd see him in showers. I had a female friend who always made comments about liking extra large dicks.

I figured I'd hook them up together, and they dated for a while. After they broke up, we got around to asking her about it, and how she liked it, etc. She confirmed he was super big, like she could use 2 fists on him and still not cover his dickhead. She showed how think with her hand, but then said that he never really got hard like other guys. they had sex, but it was like he had just over a semi hard dick the whole time. She said when giving a hand job, she could always bend it most ways. He's come like that and everything.

The next year, she told us she met another dude big like that over the summer, that was same way. Is this normal when guys are really big, they can't keep it hard? I've been like that a few times when really drunk or something, but normally very hard when arroused. I figure being really big, your body has to pump that much more blood, etc to that area and pressureize it to keep it hard.

Anyone else experience this themselves or with a mate?