Unless it froze or overheated, probably just a head gasket.
Keep your fingers crossed and start looking.
Is the oil like a creamy white color? From my experience in cars anyway when the oil and antifreeze mix it turns to a milky white color, I would think it's the same on a bike, and I would say the head gasket but could be the water pump seal I guess.
Here is what you also need to look at. On the Boulevard there is a block drain bolt located on the right side of the engine down in the V-Portion of the case. It will appear to be a simple bolt in appearance. That bolt is actually a long bolt that goes into the water jacket to drain the engine completely on anti-freeze changes. That bolt has a washer or O-Ring depending on the model. That leaks onto the block at small enough rate that it burns off as the engine is running, and it is hardly ever leaking if there is no pressure as in the engine sits there not running.
How do I know? THis one drove me CRAZY for about 4 months. I knew I was losing coolant, knew there was no steam coming out of the exhaust (meaning no water in the cylinder), yet I could smell it and knew it was loosing it. You look all over the place looking for loose hoses etc. I finally found it and even my bike mechanic was giving me props for finding it. It's a cheap fix but a maddening troubleshoot.
So look at that area and see if that helps ya. If I didn't do a good enough job of describing it is because it is 6:40 AM ad I haven't had my coffee yet.
Man that is outstanding to know
I will look for it. Today did a complete oil change and everything looked normal. I removed the tank (why did they put the damn radiator cap under the freaking tank). ???
I opened the cap and looked down with a flashlight and I could see the antifreeze. It was a further down than my finger could reach, but I could see it. I got a cup of water to fill it back up and I can say it took VERY little. Maybe a mouthful.
I think at this point I could be possibly loosing some but it would have to be very little. Like I said in my original post, I only smell it when I stop. This was the first ride of the season also.
As soon as the weather allows, I'm going to take it back out and see if I'm still smelling it.
Thanks for the info!