I saw that a year or two ago with my daughter (17 or 18 at the time). She's a huge Hitchcock fan.
For the first few minutes of the movie there were quite a few people in the theater chuckling at how quaint the idea of a woman having an affair outside of marriage being scandalous was, and there was a good deal of tittering and chortling over how far we've come as a society. I'll tell you what, though. Once that shower curtain got yanked back, every motherfucker in that theater was completely silent for the remainder of the run time.
Psycho is an amazing film. Hitchcock was firing on all cylinders, and all too often Psycho gets tossed away as a horror or slasher movie. It's every bit as well made as Rear Window, Vertigo, or North By Northwest.