Dozens of gay and straight couples smooched, posed for photos and talked with reporters while church security issued a few reminders to stay on the sidewalks.
But, as the gathering was beginning to disperse, about 35 protesters crossed onto church property and walked around the reflecting pond, eliciting a call to police by church representatives.
Kim Farah, spokeswoman for The Church of Jesus Christ of Latter-day Saints, issued a statement about Sunday's action.
"Church security asked the demonstrators repeatedly not to come onto the plaza to demonstrate," Farah said. "Though the requests were issued calmly and respectfully, demonstrators ignored the requests, and the police were phoned."