This idea have been circling in my mind for some time it's a story about a harem of Spike being a stallion it kinda goes like this:
A decade have pass after Twilight became a full pledge princess of Equestria,the lavender princess have completed all her goals in life except to have a mate. With Flash Sentry in her eyes Twilight ask her best friend Spike the dragon for help, since Spike is a guy.... Twilight ask him to guide her the 'right way' of asking a guys to a date and how to express one's feeling. In order for the two to act dating without too much attention Twilight gives Spike a magical gem that enable him to change into a stallion at will while she uses some sort of changing magics on herself to disguise herself as an unicorn. The two played dating until the two start talking their personal problems like political stress to unrequited love. Both fearing that this might ruin their friendship and remove the chance of Twilight to have her dream stallion Spike choose to ignore this feelings. While Twilight began to question her's. One night Spike saw Twilight confess to Flash Sentry her feelings and the two kiss. Devastated yet deep inside happy for his friend Spike decided to leave Twilight side and start a life of his own........ but now as a stallion he ever dreamed.
Without telling anypony Spike grabbed the title to the library he and Twilight own in Ponyville along with the magical gem that Twilight use to change him into a stallion as a way of having a new life Spike settled once again in Ponyville in order to have a life he always wanted. On his return the remaining Elements of Harmony have been captured and incapacitated by the syndicates that plague Equestria.
Fluttershy wishes to have a baby to take care off but with no boyfriend to impregnate her she decided to adopt which in turn needed money to spend on her future baby. Finding a job she landed on a cruise ship which she is said that will give her a job of a waitress........ It was no Cruise ship....... The ship was a trap to beautiful mare where they will be sold as sex slaves to rich nobles. Spike finding info of this illegal pony trafficking have disguised himself as a rich noble in order to get Fluttershy out of trouble. But things aren't that simple.
Rarity meet a rich stallion which seems to be a gentlepony and offered her an investment in his company only to be scammed by the thief in the end. Having used up all her money the mare roam the streets as a beggar slowly on he verge of insanity until Spike found her in the streets of Canterlot. With his new pony form Rarity didn't recognize him but that didn't stop Spike from trying to rebuild this broken designer. A task he seems to have second thoughts the moment Rarity starts to fall for him while Spike have no longer a crush on her.
Rainbow Dash became a victim of steroids addition after one of her fellow athletes fooled her into using it, with the griffon's words saying "They are my vitamins." Now kicked out of the Wonderbolts Rainbow is forced to do crime in order just to sustain her addiction to the said drug. She was arrested the moment she tried to rob the library believing no pony longer lived their. Thinking of some burglar Spike easily apprehended the robber in his home but he was shock to discover what have became of his blue friend. With his knowledge of medicine it was easy for Spike to cure her of her addiction all while giving her a job in the library. Because of his kindness Rainbow Dash begun to fall for him.
Applejack became vandalized of some local gang which they plan of racketeering their farm until they pay them their "protection money" not wanting to back down Applejack fought the gang single hoof with her body only getting beaten up badly. Spike one night discovered this and using his dragon powers in secret have wreck the gang apart. He then offered them his money in so they can rebuild their ravished home. Seeing generous stallion in Spike Applejack tried many times to get Spike to like him, now Spike must think of a way not to wreck a gentle soul.
And finally Twilight. Because of Twilight's eternal life Flash Sentry told her that their relation will not work for the reason that he can live all his days with her while she can not give all her days with him. As she is eternal while he is not. Saddened and feeling betrayed by her so called dream colt Twilight had finally let go of her crush to the guard. Seeing no other potential mate that can live as long as her Twilight entered a state of depression stopping her from ridding of Equestria from crimes and sins. After a long day of thinking Twilight had seen in her clarity a mate she truly desire and it was Spike. But the moment her heart seeks him now Spike no more as he is now...... Somepony else which Twilight will meet in the story.
His name I'm still have no idea what Spike alter ego would be...... Feel free to give your opinions thought.