Umm help

I comment and try to help with my knowledge and I have a completely unique situation I don’t know how to handle.

My and mate together 18 years no 3rd party ever . I have a friend I talk too and have been helping with her issues . She is a dom at home but a true switch. So I help her like I do here. Nothing but conversation. I was asked if she could ask my mate to submit to me. Still never been sexual and the context . It’s the help comfort peace , daddy dom style I carry. It’s a compliment but how do I ? This is a new one for me and hoping someone can give an open viewpoint. 100% not sexual as I don’t have that interest neither does her it’s just based on the d/s dynamic