Currently I'm thinking about how to calculate the expectation of the product of two euro option, which is
$E[(S_T-K_1)^+(S_T-K_2)^+]$
I can fit some parametric vol model from the market listed option price. The confused part is when the volatility is a function of $ln(F/K)$ (for example, SVI), how to calculate this expectation.
Many Thanks