Need advice/suggestions: How do I approach a close, like-minded female friend about a casual, no-pressure physical arrangement?

I (28M) have a close female friend (28F) from my college days. We share a very similar background, having gone through comparable life situations and breakups. We are both currently single, share similar life philosophies, and neither of us is interested in traditional marriage. We chat regularly (every 1 to 3 days) and maintain a mature, stable friendship.

I am interested in exploring a responsible, casual physical arrangement with her—specifically intimacy that focuses on cuddling, ki$$ing (lips/neck), touching, and petting, but without full se*ual interc0urse unless she is enthusiastically willing and we use proper protection.

Crucially, I want to ensure our friendship remains intact regardless of her answer. I want to approach her honestly, state my desires clearly, and give her complete space to think about it without any pressure, insistence, or awkwardness if she says no.

My dilemma is: How can I communicate this to her respectfully, maturely, and clearly without jeopardizing the strong bond we currently share as friends?