By the way, nobody can tell for sure what's gonna happen in the
future...
If it really makes you that guilty, you might wanna opt to tell him
your concern? (Though depending on who he is, this action might
lead to consequences of its own...)
My personal take is that you just treasure whatever you've got now,
return the love in kind just like in a normal relationship...
Rebound, no rebound, the future.... Like I've said, how far can you
really tell.....?