Hi K.,
Don't worry, your son will move on from this experience and will not be affected. It's not like he's going back and forth between a bunch of relationships. I am also a single mom and have been divorced for 3 and a half years. I have two beautiful children ages 9 and 6. I've yet to bring any man I've dated into my home so they've never been exposed to any new men. I have guy friends that will never be more than friends so there's no fear of they disapearing out of my children's life. I guess I've decided to focus my attention on raising them and keeping that other side of their mommy more private.
Maybe that's weird and certainly not for everyone.
Take care,
L.