DP is part of a large friend group, mostly made up of middle class professional couples all in their 30s who have young children and all socialise together regularly. DP and I were invited along to a New Year’s Eve party at one of the friend’s houses. It was made clear that all of the children were welcome and the host had got lots of party things in for the kids to enjoy whilst there. DP and I have no DC, but the majority of the other friends all brought their children along to play together.
Whilst there, I was shocked when one of DP’s friends called me in to the bathroom and casually offered me some cocaine. I’d been oblivious to the fact that they’d been regularly sneaking in to the bathroom to do this throughout the night and that DP and I were actually the only two not partaking in the drug taking. Once I became aware of what was going on I felt extremely uncomfortable being there and asked DP if we could go home, meaning we left before midnight. I should point out that DP and I have been together just over a year, so I don’t know his friend group particularly well but would never have suspected them of this. The majority of them are highly successful, well educated and appear on the outside to be doting parents.
When we left I told DP how shocked and disgusted I was that they had been taking drugs in the presence of and whilst responsible for caring for their young children. DP seemed v blasé and said that they do it regularly at social gatherings and always ensure its done away from the DC (i.e. by sneaking in to the toilet 
) so doesn’t see the problem. AIBU in thinking that this is utterly irresponsible parenting and possibly even a matter for social services to investigate?