If you really are serious, take good note of the different tones of the posts you have attracted and learn from them. They show a cross section of the views, stereotypes and prejudices you will face if you join up.
The official line is now that it doesn’t matter any more what your sexual proclivity is. However, how you exercise that proclivity must not detract from the operational effectiveness of the unit you are one team member of. Armed Services exist to deliver state sponsored violence to the state’s enemies as decisively and efficiently as possible. It is sometimes forgotten, even by those serving, that all servicemen and women, whatever their trade, may one day be required to fight and so must ultimately be willing to kill or be killed, however unlikely that eventuality may seem. This implies that those you may go into combat with must trust you with their lives, and you must trust them with yours. If you are perceived as a weak link or unreliable, you will not be trusted and so you will degrade the effectiveness of your unit until you are removed from it.
Everyone’s first impressions are dictated by the mental stereotypes they hold. John Prescott perceives anyone living in the countryside as an upper-class Tory twit. Junior ranks perceive Air Officers as only interested in their pension and knighthood. Most people perceive journalists as blood-sucking leeches. Fortunately those prejudices seldom survive actual contact with the object in question (journalists excepted).
It will be the same with you. Your success or failure as a member of the RAF team will depend on how you are perceived by the other team members after you have joined. So how you perceive yourself is very important. If you see yourself as a pilot you will be in with a chance. If you see yourself as a gay pilot you will have less chance, but if you just see yourself as gay, forget it.
If you really want to join up, and especially to become a successful service pilot, put your sexuality firmly on the need to know shelf. Whatever you decide, good luck.