I think each person is different. Definately Guy #2 needs to know your situation (that you're not divorced and it may be awhile, etc.) and that you aren't really looking for a permanent relationship. I think if you let him know you're dating other guys that might cool his ardor a bit :-) so he gives you some room. I think it would also get him to display some more of himself, whether he's "controlling" which you don't need, or just "faithful" and keeps in touch and wants to get to know you for you, etc. Who knows if you'll warm to him sexually or not, that could change over time as you get to know him.

I wouldn't worry about spreading yourself thin or letting your dates know you're dating not interviewing anyone for a permanent job :-) I think you have the perfect excuse/way to keep things to your liking what with not being divorced yet and having a child. Anybody gets too "anxious" to monopolize your time or get too serious you can get space that way and just being "busy" with other dates (they don't have to know why on any particular occasion, just that you are seeing other men at other times) will let you use this inbetween time well for yourself, playing the field, having a little fun and getting to know what you want and what is out there?