Jeff, I don't think the dreams per se were shown on the show... certainly don't remember any first season love-making scenes between L&C! I think Clark's taking some real memories -- kissing Lois in the plane (SV) and in the hotel (HiM), and being at Cat's place (SV) and mixing them up with his wishful thinking. I can imagine him lying in bed at night, planning how he'd like things to be... It's quite the fantasy life he's got going, there, though I think it's very sweet that in his fantasies, he's getting married and having kids.
"You don't know how many times I've thought about this... dreamt about this... well, something like this..."
PJ