I also have complicated feelings for this situation.

On the sex thing, adventurers don't have access to mental health professionals beyond barkeeps, priests, and prostitutes. Geese floated the idea of getting him to a brothel, since that's the go-to method of getting a distraught adventurer cheered up. He recognizes it doesn't get the guy back to how he was, but at least it's better than letting him fester in his grief. They rejected the idea of it being a random girl. Lilia was rejected as a candidate as soon as she was mentioned. Elinalise was pointed out as being an expert in these cases, but she flatly refused to do it with him. Even with disliking the mental image of Rudeus spending the night with Elinalise, Roxy pressed her on why she won't help him, leading to the elf telling her that her granddaughter is his wife. They ultimately concluded that they'll leave it be and that he'll get on his feet on his own eventually. And yes, the sex did help, but not to the degree people talk about. Just getting laid didn't fix Rudeus. It rebooted him, and the talk he had with his master right after was what got him in running order at least until they could make it back home where the real healing could take place. But that reboot has added complications to that. It was either that or let him starve to death in his room or carry him as dead weight across the desert for two months. Roxy did take advantage of him to fulfill the last clause of her fantasy "He will hear of his close friend dying, and I will be there to comfort him. That will be our first night together.", but her desire to help him was genuine. She'd fulfill her doomed fantasy, help her beloved get better, and leave his life with the negatives of her deed being her exit ramp.

I'm not for polyamorous relationship in general, but in this particular case of the world of Mushoku Tensei where they are not frown upon, and in this more particular case with Rudeus, Roxy and Sylphie, I'm not vehemently against if it makes all of them relatively happier, especially if it doesn't cause Sylphie too much trouble.

Not gonna lie I have watched a lot of reaction for this episode And yours is pretty much of the good side You really understand the situation and dont judge characters for anything without context Not like some other reactors lashing at Roxy And even though its wrong but this World has different culture and rudeus is just a bit different because hes from our world So don't worry Keep it up Have some more shows and your channel will blow up Kudos

Rudi said that if he wanted to have Roxy as a wife he should be a scumbag like Paul, he knows he is being selfish, only then he could have several wives because Mushoku is not like those anime where polygamy or infidelity is treated as something simple, where the protagonist is handsome like Tengen from Kimetsu no Yaiba and they sell you the idea that everything is fine and nothing bad happens or like 100 Girlfriends that presents it as comedy and fantasy.