Gene 'I'll Never Get Married' Simmons ... PROPOSES!!!!

7/26/2011 5:00 AM PDT
He's famously sworn that he would never get married ... but KISS frontman Gene Simmons is one step closer to breaking that vow ... proposing to his longtime GF Shannon Tweed in Belize recently.072511_gene_simmons_still_v2

We don't know what her official answer is -- but based on her reaction, we can take a guess.

The proposal -- caught on camera for “Gene Simmons Family Jewels” -- airs tomorrow night at 10 on A&E. Gene and Shannon met 28 years ago ... and have two kids together.