ExH and I have 2DCs. ExH has had a gf of 3 months. He is now away for work until the summer. The DCs have met the gf a handful of times. Gf phoned DC1 (aged 12) to invite both DCs out for a day trip with her. I have never met this woman, the children are on my time and neither myself of ExH had any idea she was intending to invite them out for the day. She didn't run it past either of us. AIBU for thinking that was a completely inappropriate thing to do and that she is majorly overstepping boundaries?