I think fancied her for a while, yes, but I also think he fancied Lisa before Lea turned him against her and probably Aisleyne for a few hours one night too. He was happy to have Nikki back because she was available and I doubt he gave Jennie much thought afterwards...the swine! Jennie probably fancied him a bit like all the girls did but that's only becasue they all think he's a special little lambchop that needs protect...then eventually they realise he's actually pretty boring. She didn't seem too upset by Nikki's return. She has her burly cage fighter to pleasure her now, possibly in a cage.
Someone over at DS has a theory that she's pregnant and that was the "secret" she was going to tell Pete(!) Which is stupid since she was still drinking heavily and involved in all the physical tasks in the house.