I think he will start to see Jay as a threat because he and Louise are close. I wouldn't be at all surprised if Dennis makes up lies about Jay and Louise to get Jay out of the way.

Well I thought it was sweet

Exactly! Pot, kettle, black Sharon! They weren't really related, but it was still weird.
However, the big (literally) problem with Denny's taking on the role would be that Louise is very tall for her age (15) because she is played by a 19 year old. She is the same height as both Ben, Jay and some of the other adult males on the show. I do believe she's a bit taller than Phil and Billy. (Honey is also taller than Billy, but then give her 3 years and Janet will be taller than Billy. I could go on, but you get my meaning. Sorry Billy-boy - how's the weather down there?, etc.)

Louise is his fxcking step-sister though!
He takes after his mum lol
I've never had my dick looked at by any woman
-Kings_Rule Innit

I'm Surprised Sharon wasn't there demanding he got the part