trishna, its always natural if a person is interested in sex... Watching a porn site doesn't mean that he got someone else beside u or he is cheating on u... may be he is trying to enhance his sexual life with u .. may be he is trying to surprise u to night with new ideas about sex.. i think all he is doing is to keep both of ur sexual life alive.. or the other reason can be cause ur are pregnent.. ur lucky that ur husband ain't leaving u and going out with other girls.. he is trying to keep it quite and make it feel home..