This porn video tag is a combination of two terms: "masosexual" and "polyamorous".
Masosexual means a person who has a strong preference for receiving pleasure, often referring to male-centered sexual experiences. In this context, it suggests that the focus of the scene will be on the males involved, their pleasure and desires.
Polyamorous refers to individuals who are in romantic relationships with multiple partners simultaneously, with the consent and understanding of all parties involved. This tag indicates that the porn video may involve a polyamorous scenario, with multiple partners engaging in sexual activity together, either sequentially or simultaneously.
In summary, this tag suggests a porn video featuring male-centered pleasure and scenarios involving romantic relationships with more than one partner.