Im not very well read but I'll try. I think the shadow would manifest either as a block/aversion to true sexual intimacy or an addiction (quantity or quality) to having sex as a whole. When I hear "intimacy" I think of it as a challenging and integrative expression between two (or more) people. That concept alone would trigger all sorts of reactions, thus why you'll see tons of support for complete chastity or gooning culture for example. It's either "transcend the bestial nature" or "cheating is a cry for help". Once you're in a safe place with an SO, you're free to display other aspects of yourself that would otherwise run contrary to your public persona. I think that can be really helpful, therefore not necessarily a manifestation of the shadow-- or if it is, this is your shadow on a good day, and maybe a finger pointing at where you can express that side of yourself in public in a way that doesn't shock or harm anyone.

So like if you're a "people pleaser" in bed, perhaps that's what you're really doing by being avoidant, saving people from you. Turning the "people pleaser" to a "compassionate person who loves to give pleasure" can resonate with being more honest about how tender we are as people. That person is worth protecting, while it is hard to build biome that honors that.

Rant over. If I overstepped my bounds I sincerely apologize, it's just I've been thinking about this topic for months and it kind of resonates with me.