Boa boner while feeding?

My boa (Columbian red tail, 3 years, f/t) Lugwrench ate a few days ago and after he'd gotten his meal into his mouth, out popped a hemipenis! About 5 minutes later, after he was mostly done swallowing, it slipped back in on its own just fine. This hasnt happened before, why did my snake get a hardon while eating?!

Note: It wasn't a prolapse. I've seen my snake's copulatory bits before and that's what it was. He is fine and active, no bad signs, he just... got excited. Why???

I guess that was a really good dinner!? And he was trying to order dessert... :rofl: Thought I'd seen it all, but apparently not...:D

It took me a while to get through this post. First I had to deal with my immature mirth over the titular phrase "boa boner." Then, I saw your boa's name is Lugwrench, and I was delighted all over again. And then I lost it for the last time at "out popped a hemipenis!," which I read in my mind to the tune of "pop goes the weasel." So thank you, for ... all of that. :rofl:

In all seriousness, I'd never heard of this happening before either. All three of my current snakes are boys, so I guess I really do need to be prepared for any and all surprises, LOL!