Quite literally, apparently.

Alan is also ‘cumming’ to Australia. Performing his popular show, I Bought A Blue Car Today,
“but a slightly different version.” Alan explains that it will be the
same show he performed during Mardi Gras in February, but “this time
it’s only going to be me and a piano and a cello. Some of the songs
have changed and stuff. It’s always kind of evolving,” says the cheeky
interviewee.
Unfortunately, I can’t take the credit for the pun. Alan uses it
himself, regularly. Most notably, and to good effect, for his fragrance
and body care range – Cumming, a range that includes such sensuous
items as: Cumming All Over, Cumming In A Bar, and Cumming Clean. Which
will all leave you, ‘of course, smelling lightly of Cumming,’ according
to the product website.
You can read more of Alan's interview at the Oz gay & lesbian website Same Same.