Even though it's allowed, it's not cool. The FAs are always willing to move the cart to allow one to visit the lav. The "2 lavs for 130 pax" is a red herring since I rarely see lines outside the Y lavs on domestic flights.

Since it's explicitly allowed (dunno what genius was responsible for that change) I can't really complain, but I do have a beef with Y pax lining up in the F cabin to use the F lav. Wait behind the curtain (physical or imaginary) until the lav is free, and recognize that F pax have priority.

I personally would not do it because I think it's cheesy, unless it's an emergency situation (which thankfully hasn't happened to me yet).

I generally don't sneer. Spitting is more satisfying and sends a stronger message.

<dons asbestos suit>