Shiro is a full believer in complete mastery of one's self. One should always strive for patience and understanding of their own soul; they should focus on what is truly around them and not they feel should be there; one should make the most out of the situation they are in, not the one they wish they were in. Patience yields focus. Focus yields peace. Everything is connected and it all starts with having yourself under control - mind, body, and soul, all together as one.
But how the everloving hell is he supposed to fucking focus when Matt is doing this to him?
It started at dinner with hands lingering a little longer than they should in places they certainly shouldn't be with his sister across the table (Pidge was more than aware of their relationship but she was very insistent they don't do anything around her, and if they did she would make overly dramatic retching noises until they stopped. She did assure Matt in private, though, that she fully supported them together). Shiro found that, somehow, these little touches got him as hot and heavy as if Matt had just decided to drop to his knees and suck him off.
Now Matt is pressing barely-there kisses up his naked thighs, the touches so light that Shiro's skin prickles with goosebumps. He really shouldn't come apart this easily. But then Matt is tracing his defined muscles with his so skilled tongue and Shiro wants to sob from frustration and ecstasy. He shouldn't come apart this easily but Matt knows every single button to push.
Matt drags his tongue, flat, along the dip between Shiro's thigh and hip, his motions slow as he hums in the back of his throat. He bites at the sharp hip bone and Shiro bucks under the pleasure with a quiet gasp. Matt spares him a glance before parting his lips to suck a deep purple hickey on his pelvis. This time Shiro full on groans as the skin quickly becomes over sensitive but the suction does not decrease; he almost whimpers when Matt pulls back with a pop, satisfied as he drags a finger over the bruise.
He looks up at Shiro with a smirk that has always promised trouble, and gotten him into trouble more times than either of them would care to count. Right now the sin it promises makes Shiro bite down hard on his lower lip as he tries to find some semblance of self control. Not unsurprisingly, there is none to be found, especially not when Matt gives the lightest of kitten licks to the tip of his lover's rock hard erection.
Matt casts him another glance, and this time his eyes are blown wide with lust. "If you beg nicely, I'll give it to you." he hums and now Shiro is sure that his composure has absolutely fallen apart.