This sounds an awful lot like confirmation bias to me, so I went to Google Scholar for about 15 minutes.

A quick scan of meta-studies seem to indicate that teenagers watching pornography mostly leads to them having slightly more sex, which is well known to be healthy.

For certain vulnerable groups of individuals (poor social integration, weak familial bonds, high risk seeking, and high aggression) porn seems to exacerbate their traits a bit.

There's also very tenuous results pointing to porn in pre-teens, as well as teens with low self esteem and poor social collection getting a skewed perception of sexuality. These are the only groups who have ever been shown to be affected negatively, and only in a single study each, without reproduction. And for the teens it reversed when they gained self esteem.

Seems we should actually have better sex education for teens so they have the support to talk and explore sexuality in a healthy manner with their peers.