Excuse for meetup

Hiya. So I'm going on a holiday for a week with friends, but there's also someone I have been talking to online who I want to meet whilst I am there. I don't want to tell my friends about it, so I need an excuse to get a few hours alone so I can meet this person. I've thought about just saying "I'm going to do some shopping on my own" but I think they'd find that strange and start asking me loads of questions since we're going to be doing everything together. Thanks for any suggestions.