It's pretty obvious that Strange doesn't like this answer. Yes, he knows that their England isn't open-minded. Yes, he knows of all the trouble that Childermass and Lambert could get into should their relationship be discovered. But dammit, he doesn't want to accept that!

"I'm certain both of you will make close friends in England who aren't me. Hell, Lambert will probably find someone closer. I simply don't want what happened with me to repeat with someone else." Even if this hypothetical person isn't as open-minded as Strange, there still would be the crushing feeling of trust being broken and feeling like they matter less than they actually do.

"Besides, the two of you deserve happiness," Strange sighs. "There must be something I can do to help you obtain it."