Boyfriend comes to bed with a wet croch after shower says it will dry. I find it gross. If I say something his penis goes soft, then our sex is uncomfortable. How do I resolve this problem other than refuse sex??

Hang a commercial hand dryer on your bathroom wall.

With some dirty talk? "Heh, that's a fine penis you have there, would you mind if I rub it with this towel? Because there is nothing more sexy than a dry crotch."

Remind him before he gets in the shower to dry off before coming to bed if he wants to  get lucky.

Have him shower earlier, so that his "Nether Region" is able to dry appropriately. If it is gross, why would you want it near you?

If you see something, Say something, and if it goes soft, so be it. Trust me, at this stage in your relationship, if a little "Hurt Feelings" turns him off, you may have to re-evaluate what you are getting into . . . Not much of a character with little stuff like the effecting him . . . It won't be long until changing the channel on his favorite commercial truns him into the "Noodle Avenger" . . .

Terry cotton sheets ?  Omg... I can't believe I'm answering this question.