David Foster's daughters Sara, Erin react to his new engagement

July 5 (UPI) -- David Foster's daughters Sara Foster and Erin Foster are poking fun at the musician's new engagement.

Sara, 37, and Erin, 35, left teasing comments on Instagram following news of David's engagement to 34-year-old actress Katharine McPhee.

David, 68, confirmed his engagement Tuesday by sharing a photo of himself with McPhee in Italy. Erin liked the picture and jokingly called McPhee "Mommmyyy" in the comments, according to People.

"Out of the country. What did I miss?" Sara playfully added.

Sara previously told Us Weekly she and her siblings "totally approve" of David's relationship with McPhee.

"We approve of whoever is going to be good to my dad at the end of the day and we're very honest about it," the actress said. "If we ever thought that anyone was in something for the wrong reasons, we would be very vocal about it."

"We just want someone that's going to treat him well and that cares about him, and I think he's with someone right now that really does," she added.

David was previously married to B.J. Cook, Rebecca Dyer, Linda Thompson and Yolanda Hadid, while McPhee was wed to Nick Cokas. David is parent to six other children in addition to Sara and Erin.