its not a one shot though... got the link from the comment below. http://www.77mh.com/colist_232092.html
(spoiler) and this pair turns kinda sweet though. having lines like "You're my precious pet" "i'll never hand u to someone else" and "you and i will be together forever". etc etc along those lines, from what i could figure out. the extra was cute~
oh and for those who are curious, after the short extra abt the dog food and being treated really like a dog, it kinda went like the seme brought the uke to attend a meeting with him so that the seme could make use of the uke for the meeting etc. (the seme was praised by his boss when it worked), after that it was sex and the sweet part where he said smthing like "relax, u're my precious pet, even if u're not trained to my ideal, i'll never give u to someone else." (rough translate)
after this is another short where the seme is leaving then the uke was saying smthing like he can't run away, more like he won't run away (the seme put a GPS thing near his ankle) and the seme then removes the GPS and proceed to declare his love for the uke, "only u can satisfy me", "i wish to keep u lock up at that place" (the first place we saw them at i think) etc etc when the uke suggested smthing abt the seme visiting his other pets (which i presume the seme doesn't have). anyways all in all the uke attempted to run away but was caught and punished.
where is the rest gaaahhh!!!!! its a very nice story!!