He's got nothing more that he needs to say - the realization that he's lucky's not one that needs to be verbalized. He lets Jack go to his room and rather than go take his own shower and then clean up, and need to shower again, he just gets busy cleaning up.

Then he can shower, track down clothes, and get out of the TARDIS. He'll use it, but it still feels weird as hell for any version of him to have one of those things. Hell, it feels wrong for their to be more than one TARDIS, period. Or at least many versions of one TARDIS.

Either way? He'll get used to it.