I'm not a huge Stephanie fan and there have been times in that house where I've felt she was just trying to act the victim and not take any responsibility for her own actions.
However with this situation I really felt bad for her.

People laughing and making out like she was dirty or gross over her underwear did seem unnecessarily mean and bitchy and a bit like school-yard bullying.
That's not to say that Stephanie has been correct every singe time she has shouted out the word "bullies", but on this occasion I think she had a point. It must have been so embarrassing for her. Yes maybe she shouldn't leave her stuff thrown about and be untidy, but there was no need for that big scene to be made. Anybody decent would have discreetly just left them back where they found them and asked the house as a whole "Could everybody go pick up their laundry we're doing a wash or a tidy up today."
Although Megan did giggle a bit she at least acknowledged it wasn't right having them on display like that and tried to cover them up with other clothing.
I wouldn't accuse them all of being bullies over this single incident but I think they handled it very badly.
I do however think Gemma IS a bully in general with people in that house and I think she does try to intimidate people like Christopher and maybe Steph too at times.
Jeremy is somebody I haven't paid much attention to as a housemate but he is growing on me a bit. He went up in my estimation as to how he handled that situation. I thought he would be a bit laddish and immature and maybe act grossed out, but the way he handled it was very gentlemanly and he made the others look like immature idiots and that they should just grow the fcuk up. He also tried to cheer Steph up with a bit of humour too.
Can't believe I'm saying this but I think he would probably be a very sweet boyfriend and really look out for his girlfriend.
(That's not condoning Stephanie cheating on her boyfriend at all, and Jeremy probably shouldn't be trying anything with somebody he knows is attached, but I'm starting to believe that he does genuinely have some sort of feelings for Steph whereas before I thought maybe it was just boredom and fun seeking and being selfish...)