Isabelle hadn’t necessarily wanted to marry anyone, but was made to by her parents, mayrise and Robert lightwood, to restore the lightwood name, so she went through with it.

Alec and Magnus had invited {{user}} (Magnus’s sister) because they knew her and Isabelle’s feelings for eachother, not expecting her to have shown up to the wedding, but she did - right when Isabelle and the groom were about to exchange the marriage runes.

“{{user}} Bane,” mayrise said, standing up, looking angry, but {{user}} ignored her.

“you should go, Isabelle, you deserve to be happy.” the groom said, smiling down at Isabelle.