> yeah, maybe Grace got some clothings for him...
Tedd's got at least one other outfit that will fit him. I haven't been able to find it, but early there was a comic where a postman was delivering a package to Tedd which was obviously girl's clothes.
edit: I was misremembering this 8/27/03 episode, where Tedd is on his way to open the front door, hoping it's a skirt he had ordered.
And add to that how on 4/15/05 when someone at school accused Tedd of cross-dressing, he answered the he never cross-dresses in girl's clothes (i.e., he TFs first). So the implication is that Tess has some collection of outfits of her own in the house.
edit: I'm not sure if these should count, but in the "fourth wall" 8/6/03 and 8/7/03 comics, Tedd is wearing a skirt (which I guess would make his 4/15/05 comment untrue).