That’s a big leap, from third purchase sippy cup to incompetent parent without modern luxuries.
sounds like you had a traumatic childhood that’s turned you bitter. Was it your Father? Mother? Both? If you can’t tell us, do you have someone you can talk to these things about?
Lets review. buying a third sippy cup, sent you off the handle to reply and talk down to this parent, going so far as to say they cant do it. that’s savage, brutal… why?