Just read Skin on Skin by Nautibitz...
Are there any other fics where Spike gives Buffy a massage, or vice vera?

Thanks

Magic Fingers by henrietta_holden. Seems like this one is a permanent WIP.

Summary: Buffy's back is killing her and she's terribly sexually frustrated so she hires Spike the Masseur to come to her house to help her out.

The Heart of Her by ClawofCat. Read the warnings!

Summary: Set sometime after 'Dead Things.' Buffy's on her period and comes to Spike's crypt to get patched up after a fight with a demon. Can Spike make all the aches and pains, both physical and emotional, go away? Warnings: A heavy dose of menstrual play and references to menstruation. This fic has been nominated at Round 6 of The Fang Fetish Awards for Best Sex, Best Angst, and Best Sleeper.

There is a sequel: Show Me How by ClawofCat

Summary: Set sometime after 'Dead Things.' After the events of The Heart of Her, Buffy is conflicted. Unsure of who she is or what she needs, Spike sets out to help her find the answers. This fic can be read as a stand-alone, but as the second installment in a series it helps to have read the previous story.

I think Spike gives Buffy a massage in The Bath Series by sabershadowkat on EF. Even if I'm not remembering correctly you'll enjoy the series!