In a happy birthday message, Gene Simmons has again invited his former bandmate Ace Frehley to take part in KISS' ongoing farewell tour, stating that the "invitations still stand" for an opportunity to "jump on stage with us for encores."

Simmons concluded his tweet to the 71-year-old rocker, who hasn't been an official member of KISS since 2002, with the obvious sentiment that "the fans would love it."

It's all stuff fans have heard time and time again over the years, as both Simmons and KISS frontman Paul Stanley have repeatedly extended an invite toward Frehley, who has remained mostly lukewarm on the idea at best. He hasn't ruled it out entirely, but has made it clear that he won't consider taking the stage with the group for a number of reasons. In the fall of last year the "Spaceman" stated he'd consider the opportunity "if the money's right and it's presented to me in the right way."

In the past, Frehley has also notoriously been opposed to appearing onstage alongside current KISS guitarist Tommy Thayer, who is outfitted in Frehley's classic "Spaceman" persona.

Even without a definitive end date to the farewell tour, time is bearing down on the members of KISS and Frehley if this reunion is to ever take shape in any capacity.

Manager Doc McGhee, who said last May that he believed Frehley would turn up in an open invitation to all past members of KISS, also forecasted last year that the band's final performance would come "some time at the end of [2022]."

Head here to see all of the band's scheduled tour dates.

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