One of the comments Lord Henry makes about women in Chapter 4 is as follows:
My dear boy, no woman is a genius. Women are a decorative sex. They never have anything to say, but they say it charmingly.
Arguably the only reason Lord Henry keeps Dorian Gray around is because Dorian is so physically attractive. He is, as women are according to Lord Henry, "decorative." Dorian likewise has little of originality or particular merit to say for himself and for the most part parrots the words he hears from Lord Henry. In this sense, Dorian Gray seems to conform to Lord Henry's idea of femininity, which in turn perhaps undermines his masculinity.
A little later Lord Henry also says to Dorian that, "As long as a woman can look ten years younger than her own daughter, she is perfectly satisfied." This might be read as an ironic allusion to Dorian's miraculous youth and also to the satisfaction that he takes in his youth. Lord Henry implies here, much as he does in the previous quotation, that a woman is defined by her preoccupation with her looks and her disregard for her mind. According to this definition, Dorian Gray is decidedly feminine rather than masculine. The insinuation of the first quotation is thus compounded by this second quotation.
Throughout this chapter, and throughout much of the novel, Lord Henry speaks to Dorian in a way which might be interpreted as patronizing and even infantilizing. He often calls Dorian a boy ("reach me the matches, like a good boy"), for example. In this way, Lord Henry reduces Dorian's masculinity to that of a boy, which is to say, less than that of a man.
Harry said many different things to Dorian in that chapter because this was the chapter when Dorian told him about his new love affair with the actress Sybil Vane, with whom Dorian fell madly in love for her portrayals of Shakespeare characters. However, the only one quote that I could think of was when Lord Henry (Harry) laughs at Dorian when he said that Sybil was "the love of his life". In a surreptitious way, Lord Henry answered while he laughed:
"I am not laughing, Dorian; at least I am not laughing at you. But you should not say the greatest romance of your life. You should say the first romance of your life. You will always be loved, and you will always be in love with love. A grande passion is the privilege of people who have nothing to do. That is the one use of the idle classes of a country. Don't be afraid. There are exquisite things in store for you. This is merely the beginning."
This was a clear sexual innuendo like Wilde fills basically all his stories with, to insinuate that Dorian is just going through a period before finding out his true sexuality.