How do you spy on someone in the shower?
Don't! That's an invasion of privacy..
When someone is not invited to a shower it does not mean that person is not liked, but it is probably the mistake of the hostess giving the shower. Sometimes the hostess has to rely on the boyfriend/husband, etc., to give a list of the woman's (who the shower is for) names if her friends and one or two often are missed.
When did it become proper to invite someone to a wedding shower and yet not invite them to the wedding?
* If you are not invited to the shower then it is up to you whether you would like to give a gift or not, but you don't have to. If you were invited, but can't make the shower then yes, you should send the gift with someone else you know that is attending or stop by and give the gift AFTER the shower to the person the shower is for.