The Doctor sat with the TARDIS doors open to view the starry sky of space, pondering where to go next when the conceal starts chirping and beeping so he got up to see what was causing the conceal to go off.
The doctor saw an S.O.S. signal and tracked it down to where it is originating from, he then had the TARDIS head to the location where the signal is spawning from after closing the doors and once there the doors open wide to reveal the master.
The doctor glared as the master walked in before saying to the master "You sent that signal" as the master looked at him and replied "You didn't have to come to the location you know, you could of ignored it yet you chose to go after it" that in turn pissed off the doctor but he knew the master was right, he could of just ignored the signal thus he allowed the master to stay because he was lonely, he notices him wearing a ring.
In a few days time the doctor notices he has spent more time looking at the master and daydreaming about him in a sexual way only the doctor ignores it, that is until he gets pinned to his bed (since the doctor was in his own room) by the master who had snuck in and started to strip them both.
The master not wanting to wait anymore thus once they were both naked he looked at the doctor and said/asked "How about we have some fun ?~" but all the doctor could do was blush a bright red and nod, the doctor watched as the master takes out a sonic screwdriver and flips the doctor onto his hands and knees.