Steris and Wayne - why must they fight?
In Alloy, Wayne mostly just likes Marasi better than Steris. He shows no open hostility toward Steris (that I recall).
In Shadows of Self and BoM, Wayne is very actively hostile and mean to Steris.
Questions are raised. Does Wayne like Wax? Is he jealous of Steris?
Personally, I read Wax/Wayne as a father/brother kind of relationship. My personal headcanon is that Wayne was mistreated for his powers as a child as Wax doesn’t get his family’s support for his own powers and they bond over that. (Canon in alloy says) Wayne is mistreated somehow for being a twinborn - I think it’s about his father or it’s all in the same conversation about his past. I think he was probably abused badly. He has a dependent personality and an addictive one - to alcohol at least, possibly pain/ this dangerous lifestyle - and obviously depressed.
I also think part of it is making sure that Wax really loves her before letting him push into this. I think Wayne knows in BoM that Wax isn’t ready and like a good friend, he stops the wedding. He knows that it’s inevitable and what’s best for Wax but he wants to make sure his friend is doing it the right way. He’s learning to move on - from Ranette, from everything (maybe thanks to Marasi).
I’m hopeful that Marasi helps Wayne through things at the end. The last thing that happens is Wayne takes Marasi’s hand and leads her away. I hope she at least helps him not just get drunk but to handle that.
Wayne is obviously lonely (I think that’s why him and MeLaan for then - depressed alcoholic makes poor choice, unsurprising and sad). Wax is pretty much all he has. Wax abandons him to come to the city and next he hears Wax is marrying this girl that Wayne has never met in a political marriage. I think Wayne is jealous of Wax (not Steris) and wants a relationship. This is Wax’s second and like Steris become Wax’s support - Wayne needs someone [Marasi would be ideal as she understands his life/ past].
It’s standard kid behavior. My dad wants a new wife so I’m going to be a child and act up and i want attention and to ruin the wedding.... oh wait, Dad really loves her, and she’s not so bad... suppose i’ll let this be and act my age.
Let’s not forget Wayne lived on the streets presumably alone until he was 16 for some amount of time and went through a lot of tauma he hasn’t dealt with. He’s clearly not handling it well and punishing himself, terribly unhealthy behavior all around for poor Wayne.
Also Wax took on a 16 year old taumatized kid and repeatably lets him act like a shield and beaten up and get abused for 16 more years... that’s also kind of messed up. Maybe Wayne choose this path and maybe Wax made him wait some years before really ‘joining in’ but this is still a traumatized kid at heart (I think) who has seen awful things from a young age, probably all the time.
Also Wax knows this, it’s obvious and Wax is obviously not the best at knowing what’s good for Wayne. We have clear signs Wayne needs help and Wax is just like ‘I don’t know...’. Wax tries. Wax is also not the best with people either...
I don’t think Wax can help Wayne. Like Wayne didn’t know how to help Wax in SoS. Steris did. I think the scenes at the beginning of BoM tell us Marasi is trying to be that person for Wayne - maybe a bit more assertive there Marasi? I think he needs someone soft who is not going to ‘knock his face off’. Poor Wayne, you’re so messed up - you need a hug, so many hugs.
Final Note: Steris is great, no one should be treated like he does treat her but empathy to him is important to understanding this situation. He does seem to get a bit better in BoM compared to SoS (maybe from seeing Steris help Wax?).
Conclusion: Wax and Wayne are like brother/father and Wayne feels Steris is taking Wax away and he hates that. Wayne is obviously depressed (and more) and not handling all this well and taking it out on Steris like a spoiled step-son. 34ish years of having a lonely physically/emotionally tramatic life can mess a person up and lead them to make poor choices.
The end. Very long. No apologies.
Mostly opinion, some facts in there for logical argument.