Bill Shenk is the husband of Tina Shenk and also the father of Dylan Shenk. He is far kinder and nicer than Tina and actually likes the Bakers. He hates Tina being rude to the Bakers and being overprotective of Dylan.
At Dylan's lame birthday party, he jokingly says ""Next time, let's book the Mormon Tabernacle Choir, too." He is not even referring to the large Baker family, but simply to the over-abundance of guests and entertainment at his young son's birthday party. A trio of professional string musicans are playing music on the patio by the pool, and Bill evidently thinks that his wife went too far in the party arrangements and invitations. His next line after this is, "Whatever happened to pin-the-tail-on-the-donkey?"
He makes his final appearance when Mark runs away and he and Dylan agree to help find him, much to Tina's annoyance.