I live with my DP and his adult son, whose girlfriend stays over at weekends. She has just got a job in a nearby town, and as she lives further away DP has told her she can stay with us "for around 3 weeks" while settling in to the new job so won't have to face the longer commute at first. However he didn't ask me about this and just told me it was happening.
AIBU to be annoyed by this or am I just being difficult?! They do plan on moving in together at a later date but no definite plans yet.