>>4439810830+, no upper limit really but personal limit for me is 50 or so
45 is pushing it but have got along with some mid 30’s-early 40’s OL/Master’s/Doctorate hags around here at a ramen place every so often, they love to talk about how nice and friendly western guys are amongst themselves when they don’t notice you hanging in the back
The JP college age exchange kids are real brats though, one openly made fun of my chopstick skills in JP to her friends right infront of me, rep corrected her right there in JP back
