Love the expressions and I'm almost certain the writing ia pretty funny. But sadly the sex in this one doesn't do that much for me as I never really got that "lets have a cute girl jack you off with a fleshlight" thing.
For those who don't understand, the plot is the sister ask the MC to tell the difference between a bunch of homemade fleshlights and the one he bought on the internet blindfolded. Of course she'll just use herself as one of these "fleshlights" at the end.