I figured the best people to ask about this were maybe other moms of teenagers. Or "mums" as this site appears to be UK-based. I'm American but I don't think geographical location really matters with this.
I'm 16, my parents split when I was 5, it's not a big deal. My mom has dated a few times over the years and has now been with her current boyfriend for almost a year now. I don't have a problem with that in itself, I have a little more of a problem with him.
He doesn't officially live with us but he's here often enough that it would be easy to make the mistake. He's a typical white middle aged man. He's not particularly unique. He's kind of socially unaware (some casual racism etc) and a bit obnoxious but objectively he could be worse. But somehow he is both horrifically boring and horrifically annoying at the same time. He's not someone I would try to spend any more time with than strictly necessary in any other circumstance. We've had a couple of minor arguments/disagreements but for the most part I just try to avoid him when he's around.
The problem is that my mom isn't happy with this. She seems to think that we should be bonding and when I was helping her with her computer yesterday I saw that she'd been googling things along those lines. Most of the things she was looking at were about step parents and much younger children. She doesn't seem to get that I'm a near adult with a near adult mind, and my issue with this guy isn't based on jealousy or anger about my dad or whatever the Internet says, but just that we don't really mesh as people. I tolerate him because he's her boyfriend and she likes him, but he's not my boyfriend - I don't know why she'd expect me to bond with him.
How can I tell her that whatever stepfather/stepson relationship she's dreamt up for us isn't going to come to fruition without pissing her off or upsetting her? I'm also afraid she might get a little bitter because I get along fine with my dad's wife and she's still weird about the divorce.
It would also be great if there was a way to ask her to not have him around so much and not let him move in until I'm out of the house because I don't want to have to be around him 24/7 like that but I'll stick to what's practical.