What is the Buddhist stand towards matters pertaining to sex, such as homosexuality and masturbation?

I have mentioned that Buddhism is largely non-judgemental. It is more concerned with what harm an action could do, rather than whether an action should be considered "acceptable" or "not acceptable" from the onset. Applying this thinking to the above two topics, one can arrive at an answer.

Homosexuality
Buddhism does not condemn homosexuality or homosexuals. Its stance towards this issue is neutral - as long as two persons have genuine mutual love for each other and influence each other positively, they should not be barred from developing their relationship.

Masturbation
Though there is no clear instruction on whether masturbation is "permitted" for all people other than monks and nuns, going by the principles of Buddhist belief, it should not be considered undesirable - as long as it does not cause adverse effects on the individual who engages in it.

It is interesting to note that masturbation for monks or nuns is an offence though. This is because such individuals are regarded to have renounced their secular lives in pursuit of the "truth", or "Dhamma", and in the process, one of the many things they must transcend, is sexual desire.