2. Sex takes a lot commitment, and with Ataru constantly chasing skirts, that's something you cannot ask from him =P
theclaw:
If the fire inspector can be kept from discovering that many zaps.
FallinG_StaR:
LoL
If Lum reaches climax... Oh boy... I'm sure that will be the 1st and last night of sex for Ataru... ;D
Talk about burning your hot-dog... or in this case instant incineration... ;D
Kroptik:
None of the above reasons.
We all know Ataru doesn't want to admit he likes Lum. Honestly, I think he doesn't even want to admit it to himself. Even if he's a huge skirt chaser, I don't think he goes as far as thinking of sex on those girl hunts, because for him sex feels like something for a loving couple. With that said, he's afraid that sex will lead him to admiting he actually likes Lum.
The electrocution risk might be there, but that's not the main reason.