The first one is from the episode "Safe," when House has been playing practical jokes on Wilson, who finally decides to get revenge (sabotaging House's cane) instead of complaining. I can't remember the name of the ep for the second one, but Cuddy needed House's help with an injection, and while he's swabbing her tuchis w/ an alcohol swab, she drily comments that perhaps he's done so long enough. The third is self-explanatory.
1) 2) 3)
See my Resource Post in my icon journal, fading_coal for Resources, and each icon has individual credits here.
Take, use, enjoy, but please credit (and comments are cool too). :-)