This is PWP. So don't expect it to be rational, logical, realistic or moral! Take it as what it is meant to be and it's okay.
The MC seems to be partly blind? Or how else did he not notice the coach wasn't wearing any pants? - Doesn't matter. It's PWP!
The MC thinks fucking is the same as love? - It happens in PWP!
It's technically harassment? - PWP! Duuuh?
One extra star for the use of lube and 0.5 stars less because the absents of a condom.
That's 3.5 stars in the end.