Efface, verb (used with object), -

1. To wipe out; do away with; expunge: to efface one's unhappy memories.

2. To rub out, erase, or obliterate (outlines, traces, inscriptions, etc.).

3. To make (oneself) inconspicuous; withdraw (oneself) modestly or shyly.

He presses his face into the hollow of your collar bone and your arms wrap around him with automatic ease. He tosses his head, rubbing his face against your cotton-covered chest, rubs and rubs and tries to slip inside your skin.

You think, with an air of detachment that is second (first) nature to you now, that he's trying to wipe his skin off so he can stain your white shirt cherry red with his blood.