Confront him face up and tell him to stop his homophobia right now and lay off your kid. It's not his place to "arrange a date", good grief, this is not the 1800's! Tell him he has the sensitivity of a lead weight and he needs to work on his people skills since he obviously doesn't understand teenagers or people who are different from him.
Oh, you meant your son.
You don't "confront" someone about thier sexuality. So far, the only thing your 'husband' has done is exaccerbate the situation and inflame how your son feels towards his stepfather. How would you feel if your father had "arranged a date" for you? (That is so many levels of wrong). Did it ever occur to your husband that a 14 year old may be exploring his sexual side and yes, some young males do masterbate with each other (I think it's personally kinda creepy, but they are curious if the other guy has a bigger one than they do or if it's different) without being homosexual. Lots of teens watch porn, both gay and straight because they are curious and this is where they are getting their sexual information since their parents are too uptight to talk to them about it!
As far as your son goes, the sooner you talk to him (at least at first without your judgemental husband hovering nearby) and let him know that you have his back, the better. Best to leave the "baby" part out. He's 14, he's a teenager and he's growing into an adult. Tell hiim that you will have his back no matter what and that if he has questions, you're open to discussing them with him anytime, anywhere. Tell him upfront that your hubby thinks he's gay but that you wanted to ask him, not take your husbands word for it. That will score you points with your son. Tell him that you love him and if he wants to talk about sex, you will be upfront and honest with him about it.
If he's gay, he's still your son and your love and support is just as important. If he's not, he's still your son and your love and support is just as important. See, either way, he's your son. My sympathy about his father, that's never easy and when you're a teen, these kinds of things are really a rough patch. But you really needs to set your husband straight, he's got a real thing against homosexuality and that can cause problems.