I don't think so. I mean, it is true that you watched him without his consentment, but as far as it has gone I don't see a problem with peeking a little. I mean, it's probably illegal and all but the truth is I don't see that much harm made so far.

HOWEVER, I do like to point out that indeed he is your aunt's husband and that is a limit that you need to respect, and you have to be honest with yourself and find out if you are attracted to him specifically or to the whole voyeur experience. If it's indeed the first one, you need to back off before it's too late so that you don't get hurt yourself or cause any discomfort (to say the least) in your relationship with your family members. If it is indeed the second posibility, then you should probably try to find a different subject to your peeping, with similar characteristics if you like, to avoid getting caught up by the first scenario.

And BTW, be careful with that taping, that could bring more problems as well.