Look, big udders flop around, especially when the girl is being boinked. When they flop around, they get into all sort of shapes don't look "normal" but it only reflect the (optical) expectation of the viewer not any sense of reality. So judging from these pix alone, I still lean towards "real".
Perhaps... precisely because they look "weird" that I tend to _believe_. It's the (near) perfect looking ones that sets off my alarm.
More to the point, I don't care. In my mind, massive boobs should droop (unless she's 16, well I don't care much for 16 years old either). If massive boobs aren't droopy and floppy (and "weird") I think they are fake. Between droopy, floppy and fake, well my preference is None of the Above, so I'd prefer E/F-cups over J/K-cups.