Assuming by "sexuality" you mean sexual behaviour as opposed to home/hetero/etc orientation then it does.
I run an after school club for teenagers and we talk about this. Now, I'll freely admit that this is run at a church and is an openly Christian group, billing itself as such. Not everyone who attends is religious but a fair few are and the ones who aren't are still the type of kids who attend an after school Christian club (if you get what I mean). Point is, I can't say with surety that their attitudes are typical.
Teenagers, males in particular, are getting a lot of their sex education from porn, and its shaping the actions they are willing to perform and shaping their knowledge of what bodies look like. There's a documentary by Channel 4 about this where they show a group of teenagers images of penises, vaginas, breasts, etc from "normal" people and solicit comments. The teenagers felt that average sized penises and breasts were small, weird looking, etc as they were solely used to seeing oversized examples that had been touched up, professionally lit, etc. Further, talking particularly to the girls here, the sexual activities they are feeling pressured to perform are far more than even I felt as a teenager (I'm 27). I had a relatively freewheeling youth and I was 17 before I had anal sex, I know of 13 year olds who aren't anal virgins. There has always been this pressure on young girls to engage in sexual activities, and there's a conversation for another thread there, but the nature of those activities are becoming more...extreme? Not quite the word I want but it'll do.
My fiance was pretty inexperienced when we got together and I noticed it in him as well. Specifically, the positions he wanted to try were pulled from porn - ones chosen to give a good view of penetration rather than because they're particularly enjoyable, for example. I'm not going to delve too deep in to my private life but there are other examples as well.
Moving away from anecdotal evidence, there's a useful summary of some of the evidence here
and if you can you should watch that documentary (it's called Porn on the Brain). I won't link it here as the only link I know of available to all is an illegal site, however if you're in the UK (and possibly the ROI, not sure) you can watch it for free on 4 on demand.
Speaking personally, I don't watch much pornography, but that's because I have pretty rarefied tastes (I want to see a woman enjoying herself and no kissing) not because I have any huge objection to doing so. I don't mind hubby-to-be watching it but I make sure I'm "involved" as it were, as I don't think becoming used to sexual gratification as a solitary activity, specifically one that excludes me, is a good thing. I know his friends do as I've spoken to them and their girlfriends about it (when it came up in conversation, I mean, not "Sit down, we need to talk about porn") and realistically I tend to dump that in the file marked "not my problem".
I dunno. I certainly don't think it should be banned even if I had a magic wand that could do so. But there does need to be more education around here. I don't feel the sex ed teenagers get in this country (the UK) is great - for a start they don't actually have any compulsory SRE until 11 - and I think a lot more could be done there but parents object. If you are in the UK there's a petition you can sign accessible from here
and I'd urge you to do so.