Ashton Kutcher is single and definitely ready to mingle ... at least in sexy ads like this one!

Demi Moore's estranged husband, 33, is getting cozy with supermodel Alessandra Ambrosio in bed for Colcci's Autumn/Winter 2012 campaign.

They definitely look incredible together! Last March, the sexy duo walked the runway for the company, and now they're the face and body of the clothing line. Nice choice, indeed!