a student visa might be a workable option or if the houseboy has skills & time to work outside in a job that would qualify him for a visa.
since the eu visa laws changed some years ago, it's much more difficult to get work visas as you probably know.
other resources you may find useful:
http://aupair-visa-france.greataupair.com/
http://www.ilga-europe.org/home/guide_europe/country_by_country/france/legal
http://www.freedomtomarry.org/landscape/entry/c/international
http://www.expatexchange.com/visa-france.html
marriage to you or someone else would resolve the issue over the longer term. the time line and other restrictions vary based on how far along the particular ER country is in regularizing their schengen laws.
prior to gay marriage being an option, some men adopted their lovers to grant them financial or legal rights, i have no idea if that is relevant in the EU currently.
depending where the boy is coming from, he might be able to get asylum or refugee status which can be lengthy capricious & expensive process.
if you have other questions you're having trouble researching, you can contact me directly, i may be able to help you find info including in french.
good luck.