Well, it's a joke, but earlier in the show Kenny was talking about how the Spurs "sweat" on people with their defense and for some reason he rubbed Chuck while he was saying this. Chuck then said "Kenny, you keep doing this I'm going to have to give you my room key."
Then later Chuck was talking about how TO (who was at the Dallas game) wears small shirts to make himself look bigger and Kenny said, "TO doesn't need to wear a small shirt to make his body look good" (something like that) and Chuck asked if he wanted TO's room key. Then they started cracking up and continued harping on it for the rest of the night.
You'd have to hear it for yourself for it to be funny.