Big Brother's sixth series has been criticised for operating "at the limits of acceptability" by watchdog Ofcom.
Contestant Kinga's conduct drew complaints from viewers
It rebuked Channel 4 for Kinga Karolczak simulating sex with a bottle and Makosi Musambasi and Anthony Hutton being intimate in a hot tub.
Big Brother presenter Davina McCall was cleared of racial discrimination over what some viewers called a hostile interview with Zimbabwean Makosi.
Ofcom also cleared programme-makers of using racial elements to boost ratings.
Ofcom received 887 complaints about the series, and 259 were specifically about the Kinga scenes.
Channel 4 admitted "the incident was a shocking one" but said it had an obligation to show the scenes to give a true picture of events in the house.
It said the images were edited so only a minimum amount of footage was seen and that they went out after the watershed following a warning to viewers.
Ofcom said Kinga's drunken antics "did amount to potentially dangerous behaviour" but because she regretted her actions and the housemates were not impressed, the message was it was "not behaviour to be condoned or encouraged".
It said the episode was not in breach of the broadcasting code.
However, it added: "We should stress that we only decided this 'on balance' and that our concerns were serious.
"This programme, in our view, along with the (scenes of) Anthony and Makosi in the pool, operated at the limits of acceptability, in terms of potential harm and/or offence for a programme of this nature, broadcast on this channel and at this time."
Makosi and Anthony's antics in the hot tub sparked 32 complaints to the watchdog.
Makosi claimed she could be pregnant and asked for the morning after pill, following the encounter.
The watchdog said the scenes did not break the broadcasting code, adding the issue of whether the pair had sex "was not the issue".
"Much of television is artificial, leading viewers to believe they have seen something that did not occur," Ofcom said.