Stairwell action

I'm at my office on a Sunday and horny as fuck.  Not really a surprise.  I start cruising to find a little action and this 20 year old college kid responds how he needs to get fucked.  Love 20 year college boys that want dick, my dick in particular.  We exchange pics and he's cute, a little cub.  We exchange numbers and he texts me when he is close.  In between making the plans and him heading over, my co-worker shows up. Grrr  Now this is fucked.  I text him to let me know when he is outside and I'll come down to get him.  He does and I tell the bitch co-worker that I am getting some food.  I get him in the building and take him to another floor and try the bathroom door but it's locked.  Instead we head to the stair well and he asks if it is safe.  Sure, no one is coming here on a Sunday (except my bitch co-worker).  We start feeling each other up and he wants to kiss.  I wasn't really feeling it but if a guy wants to kiss and you don't it can ruin the fuck.  I do for a bit before I push him down, unzip my pants and make him start sucking my cock.  He's getting it to and undoes his pants, whipping out his cock.  Smallish, but it's coo.  I pull him up and turn him around and start rubbing up against his ass.  I kiss the back his neck and he moans.  I know how to work this kid so I spit in my hand and lube my cock up and push him so he's bending over and line my cock up and start fucking his ass raw.  He's nice and tight little 20 year old ass feels good and I start fucking him hard and fast.  About five minutes in he says to hold up.  He goes over to the stairs and kneels down and uses the stairs for balance. He asks me to fuck him slower.  I enter and start long fucking him, going all the way in and taking it all the way back.  His ass feels amazing and this feels really good.  I fuck him for a few minutes and can't handle it anymore.  I blow my load about half way into him. Just as I am cumming, he tells me not to cum inside.  Sorry dude, too late.  I continue fucking him for another minute and pull out.  He rubs his ass and knows I came inside cause its leaking out my jizz. He then jacks off on, blowing his load on the stairs and he takes an elevator down and I go back to my office.  And the bitch is still there.