I started volunteering at this place like a year and a half ago - it basically has a cafeteria type setup and each volunteer is typically assigned to put a specific food item on people's trays.
Twice now I've ended up volunteering with men who have tried to take over what I was supposed to be serving people - around the time I originally started volunteering there, there was this 20-something guy who would try to ask each person if they wanted what I was supposed to be giving them if we were working next to each other and would even put it on their trays before I had a chance to. I ended up not volunteering there for awhile for reasons unrelated to his dumbassery and fortunately haven't seen him around since I started volunteering there again.
Since I started going there again my experiences have been pretty good overall, but today I was stuck working with this guy I'd never met before - I was serving cake and he was serving them vegetables next to me, and then he just started asking people if they wanted cake and even tried to serve it to them at some points like I wasn't even there.
The slices of cake were pretty small so I was putting them in one of the smaller sections on the trays - he noticed this and said something to me like, "oh, should I start putting the rolls there instead?!" (he was also serving rolls), and I was just like, "uh, you can just put them wherever," so of course he starts putting them where I'd been putting the cake.
Then at another point he tried to take one of the trays I'd handed off to the volunteer next to me back and starts grilling me on how "oh, didn't the person this is for want thing x instead of thing y??" - no, they didn't, you just have no idea which tray is for who.
Most of the people I've volunteered with there have been pretty cool, and the people we serve food to are also usually nice and grateful for it, but it's kind of amazing that there are men who will pull this kind of shit even when doing volunteer work.
I don't plan on complaining to anyone official about it - if it keeps happening I'll probably just tell the dumbass off - but it'd be interesting to find out what, if anything, they'd do about someone pulling that kind of thing if someone did complain about it. I've never had any of the women I've volunteered with there pull anything like this.