“She watches porn with me. Videos with three people or wife fucking in front of husband have also been seen. But he didn't give any response.”
Just by watching this kind of porn is actually a response in itself. She may not be telling you verbally but if she’s receptive to watching it, that can be telling you just as much. I would suggest next time you’re both watching it again, without looking at her, ask her if she’s ever thought about or fantasized about her being in the position like the girl in the porn is in. Now when you ask her, it’s very important to look at her and that you immediately make it perfectly clear to her that you could see and completely understand that you’re sure that most women probably would, and that “if” you were a woman, you’d definitely consider it, and that as a man, you just can’t help but think it’s a really big turn on, and that in total honesty, it would be even a bigger turn on to actually watch her having such an amazing experience in real life. Go back to watching the porn and DON’T say another word! Keep your eyes on the movie and wait to see if she says anything afterwards or not. Using your peripheral vision however, pay very close attention to how she acts! Watch her body movements and what she does with her hands. Her body language can be extremely revealing, regardless of what she might say to you.