Porthos has never switched to a more modern style of clothing either, apart from during one occasion - his time spent in a woman's body. The undergarments and "jeans" he had secured for himself were definitely modern, for all that he'd stuck with his own shirts as a top. He'd bandaged his breasts on occasion, but they thankfully had been slight enough not to be in the way very much.

"I've only these to lend you," he states after rooting through his closet for the pair of odd trousers. "I used to wear my own shirts, still."