Yes - but it always makes for a messy situation
Ask my Ex!
Of course. I still love all my ex partners and even first girlfriend at 15. One exception my one ex wife. She was a nasty piece of work, a real dragon. Don't ask what I was thinking. Another brain took over.
Kinda.. but not equal feeling...
Of course, it happens all the time. It's much like how you can have more than one best friend.