As for Birthday Sex... Well, it's not mandatory but it is traditional to celebrate birthdays with pleasurable activity, and more than one pony has given the gift of themselves, if you like. I don't think you need to worry about, say, perhaps Spike for several more years, though I also believe that he is due The Talk at some point in the next year or two. If you do not believe you can handle it, I would be happy to have Spike here and explain the facts of life.