I think this has to do more with a stereotype that women tend to be more clingy in relationships. Now, Although I do not believe such a stereotype exists. Your

I think this has to do more with a stereotype that women tend to be more clingy in relationships. Now, Although I do not believe such a stereotype exists. Your reasons strongly imply the existence of this stereotype. It is unfortunate if such a stereotype were to exist but I would love to hear otherwise and perhaps a better reason as to why this message is sexist. (EDIT: for clarity, you can see how an older tech savvy person having to constantly deal with a stereotype of older people being bad at tech might get offended. However, I agree with your conclusion that it would not be that big a deal because that particular stereotype is not that sensitive - and maybe a little less prevalent) To be clear, I do believe repeating, joking about and/or references to gender stereotypes are sexist.