Is it safe to give oral sex to my partner while wearing a bandaid on my cold sore?

No: There is still a chance that HSV can be transmitted to your partner this way, however the type of herpes of the cold sore is usually HSV type 1 as opposed to HSV type 2. It is preferred that no direct contact till the lesion is completely healed.

Not a good idea: If the bandaid is satuated with saliva, it may fall off or transmit the virus through the soaked bandaid. Since the sores tend to go away in days, can't you or he just wait a little longer? I think the risk is not high but why take that risk?