As far as I'm aware, Sarah's never stated she has feelings for Chad, and it'd go against what she went in for and I don't think she'd go there - not until she's ready.
Chad's made his feelings clear - he has feelings for her, but he clearly respects her boundaries by being platonic. There's a huge shift in attitude compared to his pursuits to Amelia and Sarah. With Amelia, he felt upset she mightn't reciprocate and I don't think they've even interacted since, at least not on screen. With Sarah, he treats her as a friend and is her friend, not knowing whether or not he has a chance. I'm sure she will have said she's not looking for love in the house too, maybe mentioned her supposed boyfriend off screen.
If anything, it's Deborah and Kieran 2.0. Both are close friends, and while one (or maybe both) reciprocate, nothing will ever happen. Besides, it's a lot more cuter and deeper than Jordan being paranoid Marissa will use him for fame.

Is it so farfetched to believe he has feelings? They':ve been together for over a week 24 hours a day an comforted each other in tense situations and times when the other was excluded. People enjoyed Preston and Chantelle and even wanted them to get back together during UBB. People like romances (which also happen in real life) as long as they aren't showmances, and given we've seen Sarah's interactions and impact on the rest of the house and Chad's development in how he talked to women, does it really matter if their friendship leads to more?

BIB is where I've got to reply with a few things that makes me believe that personally Chad is looking for a Showmance.

1. I didn't like Cryandtelle and Preston on UBB, and I doubt that I would on CBB4 where Cryandtelle isn't even a Celeb so shouldn't even be meeting Preston.

2. I'd buy that Chad had real feelings for Sarah if it was his first one that he said something about, or it wasn't a few days after his chances with Amelia ended, this to me isn't natural and makes himself and the show look a farce to me.

3. I have no problems with romances if they're real, I've never complained about Helen and Paul BB2 or Grace and Mikey BB7, or Sophie and Lee BB3. I hate scripted romances quite alot though, even away from Reality TV as it's just never done in a believable manner and Chad's so called feelings of Sarah is happening way too fast for it to be believable imo.

As I've already said, Chad's not a nasty guy on the show, if I was living with him I'd be perfectly okay with him, but to watch this is all he is going to offer you is The Batchelor, he isn't a proper Housemate.

1. People did though, and that was 11 years ago now. Enjoyable howmances are no stranger to Big Brother, but there's few

2. His feelings for Amelia weren't serious , and I doubt his for Sarah aren't, either. He was/is close both to Amelia/Sarah, but for both friendships he was friends woth them for a few days before admitting his feelings. It's not unreasonable for him to be attracted to a pretty woman who he spends a lot of time with - but since they barely knew each other, he didn't need time to recover from Amelia (and possibly Sarah)

3. He admitted feelings after a few days, but I'm sure he called her pretty on Day 1? I'm sure he at least said he could get her. Also I just doubt it's a showmance since it doesn't seem scripted? If it was scripted Sarah would state her feelings out front surely? Charah's friendship /relationship juxtaposed with AmeliaXChad and MarissaXJordan shows that it isn't scripted -and if it is, congratulations to the producers not making it like Marnie and Lewis/Marnie and Kieran/Marissa and Chad. It's certainly a different dynamic to the generic ones

Well that's your view. I think Chad's more 3D and has more substance since he's reigned in his arrogant side and treated women with more respect, and he's simply providing with just his friendship alone at the minute. Until Sarah acts or reciprocates (which I doubt will happen) I can't see her a showmance happening. Right now theu're just two friends who feel isolated and enjoy each other's company. And when TiBB hates showmances and the majority like Chad, he must be doing something right

1. It seems like the public were more naive back then with Prantelle.

2. He only stopped chasing Amelia because she picked Sam over him because he got booed from the crowd, otherwise he would still be up her ass.

3. Chad's landed lucky that he is playing the Showmance route with the most popular Housemate in the series as it always spares the public's wrath otherwise, I mean look at what it did for Faye BB12, John James BB11, Dimitres BBCAN, and Neda BBCAN (if you've ever watched/heard of the Canadian series) they all paired up with their year's most popular Housemate who then carried them through any public votes that they had to face. People seem to pick and choose when it's okay to Showmance and it's happening again here as Chad would be lambasted in any other year with most of the other female Housemates if they was even remotely controversial with the general public.