Is it normal to have an odd tingly feeling when seeing people/characters touch?

When watching TV or movies where characters with whom I feel very connected/attached gently touch each other in an affectionate/romantic way, I feel this brief pleasant, tingly, shiver that starts in my head and quickly sinks to my stomach. Almost like a mini "brain orgasm," if that makes any sense.

The touch can be as innocent as a comforting hug, but it only works when I see convincing romantic chemistry and sexual tension between the characters and can identify with one/both of them. For instance, I'm an X-Files fan and whenever Scully and Mulder have an affectionate physical moment. There are many other examples, too.

The same occurs when I see close friends touch their significant other sweetly or someone I'm interested touches me gently. Sex doesn't really do it, nor does kissing/being sexual with someone I've been dating for awhile. But with someone I have even the slightest non-platonic feelings for, rubbing my shoulders, brushing my hair out of my face, holding my hand, or even a well-meaning touch on the arm can do it.

I hope that made some degree of sense, I find the feeling hard to describe and the times it happens are sort of specific.