So... does your boss have good taste, at least?

There's nothing wrong with that! You can never stop being sexy ;)
Good for her!

Make sure whatever you get, it's crotchless.

She might not have the time or the range-of-motion to drop trou in case the lingerie works on an unsuspecting target.

Give the woman what she wants!

Big deal. 70 somethings have sex lives, too.

... and?
It's not like she wants you to watch her try it on

That seems like an inappropriate thing for an employer to ask of an employee regardless of age.

What the hell is your job? I mean, there is nothing wrong with a 70 yr old having a sex life, but I can't think of an expertise where ordering lingerie for your boss off magazines would be in your contract. Seems like a rather innapropiate request at a workplace. Or anywhere really?

So apparently bosses and their employees aren't allowed to be friends with one another and ask each other for gifts?

"I'm a guy." Now THAT would be legendarily awkward.

I don't see why this is a problem unless you're picturing your boss in that lingerie. In which case STOP IMAGINING YOUR BOSS IN LINGERIE!