Ah, gotcha. Well, I can offer to beta the scene for you if you want (wow! the one time I'll be able to use the "has written a lotta smut" line on my resume!). Otherwise, I'd suggest avoiding more concrete description if it makes you uncomfortable. That's not necessarily too hard. There are even instances where you can get away with "him" for penis and it's perfectly clear that you're not, y'know, talking about the whole dude: "She took him into her hand." That sort of thing.

And hey, I finally thought of another penis-word that I don't hate: shaft. It's not very versatile, though. You don't want to be, like, "She looked down at his shaft." *snicker*

Ooh! Or, you could play up the hardness angle. And...that's probably more advice than you really wanted from me.