Feminists have poisoned relations between the sexes to such a degree that opening a door for a girlfriend is considered sexist.
OMG, she is not a weak little girl, you pig! She's a strong woman who slays dragons. She can open her own door.
Somehow, a simple, reasonable, polite act is twisted into something that is wicked. The following tweet is similar in that regard:
White people can’t wait to put the grocery divider on the conveyor belt at Kroger... bitch I don’t want yo raisins too close to my ramen noodles anyway— Pierre Savage-Hunter (@PrettyboiiDB_9) 17 August 2018