Humping after his bath

A great theory folks, but Aonghus absolutely despises being bathed. He hates it! I don't think he's thanking me, and now he's trying to hump my leg. He has gone off the deep end. How do I deal with the annoying and embarrassing behavior?

 

I would most definitely NOT want to use him as a stud. He is very neurotic and a little nuts. Also, he is a rescue, so he is not stud material. But to be honest, I worry about leaving him at the vet without me there. He is a runner and his recall is practically nil, I worry that he might get loose and I would lose him forever. I know, it is a crappy excuse, but it is something that has bothered me since he got old enough to neuter.

 

None of the 3 vets in my area will do that. The all want to keep him overnight and there are no fenced areas to walk the dogs. That is the reason that my dear boy is still intact. I would rather deal wit the issues involved with him being intact than I would the heartache of losing him. Are there any good behavioral techniques to deal with his "problem," or should I just ignore it and hope it goes away?