Interesting question. I hope you don't mind me answering...because in the scenario, the 'guy' would instead be a woman. But I have thought about this before, and I think it would very much depend on if it's something she would be interested in, and the kind of tickling. Her being tickled by someone else doesn't bother me if it's friendly and she enjoys the playing. If the nature of it is flirtatious or intimate, that isn't something I would want to watch, and I wouldn't be happy about it. I can't imagine a scenario where I would want to watch her being tickled by someone else. If you don't want me to vote (i.e. you only want ladies with guy SOs to vote) then I won't, but the answer for me is no.