Ash, I think your stating of that boundary - and the way you worded it - was excellent. What are you prepared to do if/when S tells you that boundary was violated? What are the consequences?
Tough questions, but exactly what positives result from S spending time with H? Does S want to spend (alone) time w/H?
Strength and honor. (why is "Strength and honor" said exclusively to/by men on this forum, anyway?)
Strength and honor, Ashlee.
Gardener
"My soul, be satisfied with flowers, With fruit, with weeds even; but gather them In the one garden you may call your own." Cyrano deBergerac