Even if she had a truly valid reason, it will still be a pretty stupid mov
e without letting him know in advance or at least a text from her side if she wanted a good relation with MC. The message she did send intended or unintended was pretty clear to MC. Christian of all people was more important to her as him even on his big day.
That is something else though, that she intended it to end as it did and leading to the event of the party and what happened there where MC also has his share of the blame to go around and she was stupid enough again to invite rapeboy to MC's graduation party after what happened on gameday and reaction of MC on gameday without even a headsup with Mc prior.
Sure she had that right in principle though then might have been even better to just stay away completely as appear with Rapey after what happened, but again something that sends a negative message to MC even if MC had not loved her or not read her phone leading him to go bananas at the party