Beyoncé Concert Bathroom Break Nearly Ruined Lil Rel Howery's Proposal to GF

Lil Rel Howery says an ill-timed trip to the men's room almost spoiled his marriage proposal during Beyoncé's concert ... and he's thanking her for stalling long enough for him to pop the question.

The comedian joined us Wednesday on "TMZ Live" and told us all about how his engagement went down ... and why nature called at the most inopportune time.

Lil Rel proposed to his GF Dannella Lane at Beyonce's concert Monday night at SoFi Stadium, and he says Jay-Z and Beyoncé's mom, Tina Knowles, advised him to do it when she sang "Love On Top" ... and they arranged to get the moment on the stadium's big screen.

It's funny, Lil Rel says he was waiting for the song for so long, he finally needed to break the seal ... and as soon as he got to the bathroom, "Love On Top" started playing.

Lil Rel says he finished his biz, and rushed back to his woman ... but he couldn't find their seats!!!

With the clock literally ticking, Lil Rel says he had to go back out and retrace his steps, and when he finally got back to his seats a cameraman was waiting ... and Beyoncé was motioning for him to get on with the proposal because she was dragging out the song. 😂

It all worked out, since Dannella said "Yes," and he tells us how the plan to propose really came together at the last minute. As for whether Bey's forgiven his tardiness ... we'll let him tell it.