Can homosexual monks or nuns ordain, if not WHY?

*Namo Buddhaya! (I am a Theravada Buddhist)* The Vinaya says monks & nuns cannot be together in private (it would be an offense). > But what if someone is a homosexual, **how would they go about > ordaining**, as they would not be able to technically be with men then (similar to nuns)? I would have a hard time believing the Buddha would discriminate against someone who is a homosexual. **IF** they cannot ordain, > what is the **reason** that they can't ordain as according to the Buddha? ( WITH SOURCE) The Buddha chose to ordain woman, and homosexuals for sure can overcome their sexual urges just as a woman can towards men AS WELL, so why can't homosexuals ordain? (Please, if possible, cite sources!) Metta!