Anderson East turns 30 on Monday (July 17), and what better way to celebrate a major life milestone than with an amphitheater full of fans -- oh, and Miranda Lambert -- singing to you? Lambert orchestrated that exact moment for her boyfriend during a Sunday night (July 16) concert.

East is currently out on the road with Chris Stapleton for Stapleton's All-American Road Show, which stopped in Buffalo, N.Y., on Sunday night. Lambert was in attendance to be with her boyfriend on his birthday, and near the end of East's set, she came out onstage to help the audience wish him a very happy birthday. Readers can press play above to see video of the moment; earlier during East's show, Lambert was spotted watching from the soundbooth.

East and Lambert went public with their relationship in early January of 2016. On Valentine's Day in 2016, the two performed the classic Mariah Carey anthem “Always Be My Baby” together during one of East's shows, and just a couple of months later, Lambert surprised fans by joining her beau and Morgane and Chris Stapleton for a cover of the Temptations hit "My Girl." East also joined Lambert, and Lambert's father, onstage in Chicago in late January.

East and Lambert both reappeared onstage during Stapleton's set on Sunday night as well: She sang "Fire Away" with him while East -- carrying black balloons that spelled out "30" -- hung out briefly onstage during "Tennessee Whiskey." Crew members also tossed black balloons into the audience in honor of East's big birthday during that same song, causing Stapleton to crack up.

Stapleton's All-American Road Show is keeping him busy on the road this summer, though a few stops on the trek had to be postponed, from June until later in 2017, due to a hand injury that Stapleton suffered in late May. In addition to East, the Brothers OsborneLucie SilvasBrent Cobb and Margo Price are all acting as special guests on the tour. Cobb and East both played with Stapleton at Sunday night's show; Stapleton also shared a brand-new song, "Trying to Untangle My Mind," during the concert.

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