I didn't downvote you, but this seems extraordinarily unlikely to me. Why would our extraterrestrial overlords want to use us as slaves? They travelled a long way to get here, surely they should have robots or a genetically engineered underclass or something. We're in the process of making human labor obsolete ourselves. The only scenario I can imagine where this makes sense is one where the aliens have interstellar travel but lack decent genetic engineering, and they're interested in exploring/building/mining in places that are inhospitable to both their own biology and robotics but not our biology (like a planet whose gravity would crush them that also has an EM field that would fry circuits without exceptional shielding). This seems like a stretch to me. I feel like wiping out a potential future threat is a much more reasonable incentive, with exploitation/study of an already existent biosphere being a runner up. Most of the things they could want humans for would be more efficiently accomplished by phytoplankton and krill. You're right that nigh-perpetual enslavement is the most horrifying possibility, it just seems implausible.

Bondage, you say? Sounds like Rocky Horror Picture show.

The point is not some specific fate, but that anything could happen. And anything includes loads of bad outcomes , most of which we are probably unable to imagine.