The post’s author, Natalee Cooper, was out with five other friends when the incident took place at The Emporium Bar on Elm Grove in Southsea.
The post, which has been shared more than 2,000 times, claims that a male ‘manager’ burst into the bar’s toilets, where four of them were chatting while the new mum, Natalie Reade, was in a cubicle expressing milk with a breast pump.
He then ‘insinuated’ that they were doing drugs – which Natalee strongly denies.
Describing the incident at about 6.30pm on Saturday, Natalee, from Waterlooville said: ‘They say men and women might come into clean the toilet, but there was no warning or “girls, I’m coming in...” He literally just barged in.
‘We were just in there having a laugh, taking pictures and things.
‘But it was his attitude and the way he was shouting at us.’
To prove it was just milk, two of the friends, plus another woman also there jokingly drank a tiny amount of the breast milk, which Natalee says the man bizarrely compared to spiking a drink with a date-rape drug and branded them ‘disgusting’.
When the women were back at their table, the manager saw a small amount of liquid spill from the now cleaned pump as Natalie tried to put it back in her handbag.
He came over and accused them of ‘squirting’ milk. He then snatched and broke the pump before ordering the group to leave.
But Natalee added: ‘We weren’t being confrontational, we weren’t fighting or smashed drunk.
‘We’d been in [Osborne Road bar] Rapscallions earlier and Natalie had been expressing at the table, and there was no problem. The staff there were lovely.
‘If she doesn't express regularly it can be very painful – and it can be dangerous.
‘It was Natalie’s first time out since having her baby. She was so upset after this though, she just wanted to go straight home. She had no other way of expressing milk now anyway, so she had to get a taxi back to her home In Southampton.’
‘There’s been no apology, no offer to replace the broken pump. That’s all we wanted.
‘Since this went viral, we’ve had so many messages of support.’
Natalee exchanged private messages with an unnamed person behind The Emporium’s Facebook page, which claims their problem was with squirting an ‘unknown liquid’ from the breast pump ‘into a member of the public’s mouth.’
She added: ‘I’ve sent them three private messages since then, and I know they saw them, but they didn’t reply. Now they’ve blocked me.’
The News has been unable to speak to anyone from Emporium despite repeated calls and messages.
A post at the top of their Facebook page says: ‘We do not and have not ever had an issue with expressing or breast feeding.
‘We hold events here like children's parties and also baby showers and these things are expected so it would be no different on a Saturday evening.
‘Our toilets are attended by both male and female attendants which is stated on signs.’
Under The Equality Act 2010 it is discriminatory to treat a woman unfavourably because she is breastfeeding.