Perhaps my most emotionally challenging appointment ever was with a client who had terminal brain cancer. His best friend (who was previously his partner), hired me to spend an hour with him in hospice care. He was within weeks of passing, and his friend just wanted him to have one last opportunity at intimacy. We didn't do much, mostly just laid naked and cuddled. He was in and out of awareness due to extreme cognitive diconence.
I left with mixed feelings, hoping that the memory and experience would linger, but also knowing that he will likely forget about it quickly. Either way, I celebrate that I got to share the time with him. His friend emailed me about a month later informing me of his passing and thanking me again for being there for him. I still tear up thinking about it, as I am right now, as I type this.