Despite being a bit grumpy about the titjob, Myrrha was very competent at it. She was in fact so good, that your pent-up self exploded it a fountain of jizz covering her breasts and a good shot landed on her grinning, surprised face.
Myrrha didn't expect the sheer amount of semen you produced and seemed quite proud of her performance. At least you made her smile, you thought to yourself, that could be a good start for more shenanigans with her.