“M’lady, may I gently suggest you trim the hedges of your nethers?”

Serious answer:

I was the lady in this situation.

Just say you’d love it if she trimmed tight or shaved. She can always say no, you aren’t attacking her, just expressing a preference. Same as if she said she’d love you to shave, right?

Just grow out a nice thick beard and go down on her until she turns the tables on you.