There's a thread ongoing about girls talking about dick size and the like, but this is a variation: how about vids in which a girl is getting nailed, or perhaps even giving a blowjob, and she comments that it feels like the guy's dick is getting bigger (or harder). The scenario here is that the guy was already hard and apparently fully erect, but for whatever reason seemed to get harder, perhaps thanks to the girl really turning him on, or it just feels to the girl as if the guy got bigger all of a sudden.
The third video on this page illustrates exactly what I'm talking about (it's also a very cute moment where the girl breathlessly asks "How the fuck did you do that?")
http://www.wannawatch.com/hosted/giantsblackmeatwhitetreat_mov176/
Another variation on this theme might be clips when the guy puts it in while perhaps it's still soft-ish and then gets hard while inside the girl ... but I've never actually seen this in any clip (not counting BJs where the guy starts soft and the girl makes him hard that way).
