I am configuring Odoo website for my company eCommerce. We  sell products that can be "right" or "left", this is configure as products variants. We also want to sell pairs (one left and one right) with a discount. On the website I want the three options. 

In stock inventory I want only have "right" or "left" products but not "pairs" so add a new variant is not suitable

is it possible without create a module, with some configuration?

I am newly at Odoo, thanks on advise