I've watched straight porn a few times to see some actors I thought were attractive: James Deen and Jordi el Nino Polla.
I've watched some bisexual porn - I really like Shifting Gears with Cameron Marshall.
The thing I don't get - and I've asked straight male friends about this - is why do all the female porn actors look like Barbie Doll Whores. (I get that drag queens are imitating them with the garish make-up and big artificial hair). Why not have a fantasy about a policewoman who looks like an actual policewoman or a nurse who looks like she works for a living - trust me 6 inch stilleto heels are not something you wear when you'll be on your feet for 12 hours. It's always the 'slutty' hallowe`ew costumes, the chemical damage hair, shaved body/public hair, and make-up applied with a putty knife.
I think i could handle looking at a woman who looked like an average woman. These sex-dolls hit the uncanny valley factor for me.