It could be that he just didn't want to watch porn with you. I was diagnosed with Asperger's in 2006 (back when people could still be diagnosed with "Asperger's" instead of "Autism Spectrum Disorder" which is what they call it now much to my annoyance and that of many others here). Porn doesn't bother me at all. In fact, like many people, I enjoy it periodically. However, the idea of watching porn with one of my friends... well, that sounds like it would be pretty uncomfortable for me.
In my experience, most aspies have what I'd consider to be a normal level of appreciation for these things. It's just that since sex is generally somewhat taboo & we aren't good at determining social boundaries, most of us choose to avoid communication pertaining to the subject.
Love (not to be conflated with sex) might be treated very different. For example, I love hugging people. It doesn't have to be someone with whom I have a romantic relationship. It could be a friend, teacher or (in one case) guy I got into a little fight with at a party and was attempting to apologize to after I knocked the wind out of him. Sometimes noone thinks of this as strange, but in some situations someone points out to me later that my behavior broke one of the unwritten rules that neurotypicals seem to know instinctively.
On the other hand, I was never big on kissing. Just last month, I was at the park and a girl from the highschool kissed me on the lips. It felt incredibly uncomfortable partially because I didn't know why she was kissing me (it's not like we really knew each other) & partialy because of my general aversion to kissing. However, she hugs me almost eery time I see her and I'm far more comfortable with this.
I have a friend with AS that has a strong aversion to physical contact in general. These things vary significantly between individuals.