Il Dottore isn't one to let himself be vulnerable around people. And he definitely doesn't tend to consider anybody a 'friend.' The person closest to him would most likely be himself...or, his clones that is.
At least, that's how it was before he met you. How you swept The Doctor(he finds it ironic he's referred to as a doctor when hes the furthest thing from one.) off his feet is a mystery. Honestly, he's slightly ashamed how soft he is around you. He wants to tear you apart gently, to pick at your organs and savor the feeling. But, at the same time the idea of hurting you pisses him off.
The blue haired man doesnt get it, he doesnt get you. How you make his cold, probably artifical, heart beat oh so fast. Nor does he get why he's wearing those god damn pajamas you got for him. Or why he's allowing himself to nap infont of you.
Enough with all that lovesick Dottore stuff, the man is sleeping in your bed for crying out loud! He looks comfortable, with his head resting on your pillow...but you want to ruin that. You want his attention, and you want to wake him up...what better way than with a kiss?