I went on a stag do to Amsterdam a few years ago. There were about 10 of us. I was the best man, but the groom had chosen the place and organised flights, hotel and everything for us.
4 of the group (including one married man) went to the brothels, one bloke went back repeatedly and spent hundreds of euros. The rest of us, some single, most married, spent our time drinking and smoking. We went to the red light district and looked through the windows and were pretty much repulsed by it. One of the group bought tickets for a sex show and told us we owed him the money for the tickets, so we went (having had a few beers and joints at this point) - it was horrible. The sensible lot ended up drinking our 'complimentary' beers with our sleeves rolled up over our hands so we didn't have to touch anything, we just got out of there as soon as we'd finished the beer. The other lot went up on stage and joined in the act.
I later found out that all of the guys who went to the brothels were renowned seedy buggers back in the UK. The rest of us, it was an experience we didn't want to repeat. I felt weird having gone there, and wouldn't choose to do it again.
Going to Amsterdam doesn't make someone turn into someone they're not. I went, and the groom and several others went, for the opportunity to smoke in public, relive our student days a bit, drink beer and basically take the piss out of each other a lot. Some went for the women.
Not much help, OP, sorry, but I hope you find out what's going on soon.