Kathy, if I might offer an idea, she is on anti depressants and has a hard time dealing with the pressures of life, what you are putting on her is adding to that pressure, don't make her decide, if you want the panties go get them, put them in your drawer in plain sight, after all she knows you want to wear them already. Now don't wear them just yet, wait and see if she is bothered, if not quietly start to wear them with out making a thing about it. she does not have to make a hard decision about something she does not understand. It might make it a bit easier for her. Either way I wish you luck with it.
Tina B.