I may have made a tactical error

Have sworn at housemate. Am torn between wanting to apologise (swearing at people bad) and saying 'fuck it' on account of, having lived with me for a year and a half, you think she would have got that while panicking over USB it's not a good time to say I'm stupid for backing things up, and when I leave the room in order not to lose my temper (see I tried) to follow me to repeat said statement.

My Mum and Nan do it too, but I'm bound by a certain level of filial respect (and utter terror) so I don't swear at them. Friends are supposed to be less dumb in these matters than family.

Will probably apologise for swearing at her tomorrow when I have calmed down. Maybe. Still majorly pissed off at her.