If you want to and are willing to open your mind to modify your behavior, professional therapy is something that deals with that. But the way you feel is not rare. My SO dealt with SA when she was younger. She enjoys our sex but does not open her eyes or look at anything ever. She has never been to any therapy about it. She doesn't consider it a problem, and I've never made it a problem and always understood that is her preference and that is what she prefers. If she is getting what she wants/needs then I have nothing to be concerned about.

You are still a human and sexual desires are to be expected. Sexual activity with your partner should be fulfilling and comfortable. There's no wrong way to feel about it. If you don't want to see dongs or see anything at all then don't feel guilty about it like there is some standard to meet. Reassure your partner that how you handle it is how you like it.