Fans can't stop talking about KISS frontman Gene Simmons' proposal to his longtime partner, former model Shannon Tweed, on last night's episode of Gene Simmons: Family Jewels. Simmons has been in a 28-year relationship with Tweed, and the couple has two teenage children together, but they've never officially tied the knot. The proposal seems heartfelt, but the event has inspired a lot of doubters who believe it's just a publicity stunt—especially considering their very frosty behavior during a press junket for the show in June. Simmons' Twitter feed is equally cryptic about the upcoming nuptials: "We are taking it day by day," he tweeted after the show aired. "Stay tuned."